Systems and Methods for Controlling Radio-Frequency Exposure

ABSTRACT

A wireless network may include a base station and user equipment (UE). The UE may transmit uplink (UL) signals to the base station using a dynamically adjustable maximum UL duty cycle. When the UE identifies that a user is in proximity to the UE, the UE may transmit an indicator to the base station. The indicator may identify that a radio-frequency exposure (RFE) event has occurred and/or a suggested maximum UL duty cycle that would allow the UE to satisfy limits on RFE. The base station may limit a UL grant to the UE so that the UE performs subsequent communications using the suggested maximum UL duty cycle or a different maximum UL duty cycle. Coordinating adjustment of UL duty cycle in this way may allow the UE to meet limits on RFE without requiring the UE to perform maximum transmit power level reductions.

FIELD

This disclosure relates generally to wireless networks and, moreparticularly, to wireless networks having electronic devices withwireless communications circuitry.

BACKGROUND

Electronic devices often include wireless communications circuitry. Forexample, cellular telephones, computers, and other devices often containantennas and wireless transceivers for supporting wirelesscommunications. The electronic devices communicate with wireless basestations in a wireless network.

Electronic devices with wireless capabilities are typically subject toregulatory limits on radio-frequency exposure. It can be difficult toprovide satisfactory and efficient wireless communications between thewireless network and the electronic devices while ensuring that theregulatory limits are satisfied.

SUMMARY

A wireless network may include a base station having a correspondingcell. User equipment (UE) devices may be located within the cell and maycommunicate with the base station. The UE devices and the base stationmay communicate using a communications protocol such as a 3GPP FifthGeneration (5G) New Radio (NR) protocol. A UE device may use antenna(s)to transmit uplink (UL) signals to the base station using a maximum ULduty cycle. The maximum UL duty cycle may be dynamically adjustable. Thenetwork, base station, and UE device may rapidly coordinate dynamicadjustments to the maximum UL duty cycle.

The UE device may perform proximity detection operations to identifywhen a user or other human body is in proximity to the UE device. The UEdevice may transmit an indicator to the base station when the UE devicedetects a user or other human body in proximity to the UE device. Theindicator may identify that a radio-frequency exposure (RFE) event hasoccurred, such that the UE device may need to adjust UL transmission tocontinue to satisfy regulatory limits on RFE. The UE device may identifya suggested maximum UL duty cycle that would allow the UE device tocontinue to satisfy the regulatory limits on RFE. The suggested maximumUL duty cycle may account for pathloss between the UE device and thebase station if desired. The indicator may identify an RFE levelproduced at the UE device. The indicator may additionally oralternatively identify the suggested maximum UL duty cycle.

The base station may process the indicator to confirm that the UE devicecan use the suggested maximum UL duty cycle or to identify a differentupdated maximum UL duty cycle for the UE device. The base station mayadjust a UL schedule for the UE device that limits the UL grant to theUE device so that the UE device performs subsequent communications usingthe suggested maximum UL duty cycle or the updated maximum UL dutycycle. If desired, the base station may provide a feedback signalidentifying acceptance of the suggested maximum UL duty cycle oridentifying the updated maximum UL duty cycle. Coordinating adjustmentof UL duty cycle in this way may allow the UE device to continue to meetthe regulatory limits on RFE without requiring the UE device to performmaximum transmit power level reductions, thereby optimizing ULcommunications and throughput for the UE device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of an illustrative electronicdevice having wireless circuitry for communicating with a wireless basestation in accordance with some embodiments.

FIG. 2 is a diagram of an illustrative cell having a wireless basestation and user equipment that communicate using steerable beams ofradio-frequency signals in accordance with some embodiments.

FIG. 3 is a flow chart of illustrative operations that may be performedby a base station and user equipment in using the physical uplinkcontrol channel (PUCCH) to coordinate a network-determined dynamicmaximum uplink (UL) duty cycle adjustment for the user equipment inaccordance with some embodiments.

FIG. 4 is a flow chart of illustrative operations that may be performedby a base station and user equipment in using the PUCCH to coordinate auser equipment-determined dynamic maximum uplink (UL) duty cycleadjustment for the user equipment in accordance with some embodiments.

FIG. 5 is a flow chart of illustrative operations that may be performedby a base station and user equipment in using the physical random accesschannel (PRACH) to coordinate a network-determined dynamic maximumuplink (UL) duty cycle adjustment for the user equipment in accordancewith some embodiments.

FIG. 6 is a flow chart of illustrative operations that may be performedby a base station and user equipment in using the PRACH to coordinate auser equipment-determined dynamic maximum uplink (UL) duty cycleadjustment for the user equipment in accordance with some embodiments.

FIG. 7 is a circuit block diagram of illustrative wireless circuitry onuser equipment for generating radio-frequency exposure (RFE) levelinformation and uplink duty cycle information for transmission to a basestation in accordance with some embodiments.

FIG. 8 is a table showing how illustrative user equipment may identifydifferent optimal uplink duty cycles for different pathloss environmentsin accordance with some embodiments

FIG. 9 is a flow chart of illustrative operations that may be performedby user equipment to report RFE level information and uplink duty cycleinformation for use in coordinating maximum UL duty cycle adjustments orother network adjustments in accordance with some embodiments.

FIG. 10 is a table showing how illustrative user equipment may identifydifferent RFE levels for a base station using different media accesschannel (MAC) control element (CE) indicator values in accordance withsome embodiments.

FIGS. 11 and 12 are tables showing how illustrative user equipment mayidentify requested UL duty cycles for a base station using differentmedia access channel (MAC) control element (CE) indicator values inaccordance with some embodiments.

FIG. 13 is a flow chart of illustrative operations that may be performedby a base station and user equipment in using a MAC CE to report RFElevel information for the user equipment to the base station inaccordance with some embodiments.

FIG. 14 is a flow chart of illustrative operations that may be performedby a base station and user equipment in using a MAC CE to report UL dutycycle information for the user equipment to the base station inaccordance with some embodiments.

DETAILED DESCRIPTION

Electronic device 10 of FIG. 1 may be a computing device such as alaptop computer, a desktop computer, a computer monitor containing anembedded computer, a tablet computer, a cellular telephone, a mediaplayer, or other handheld or portable electronic device, a smallerdevice such as a wristwatch device, a pendant device, a headphone orearpiece device, a device embedded in eyeglasses or other equipment wornon a user's head, or other wearable or miniature device, a television, acomputer display that does not contain an embedded computer, a gamingdevice, a navigation device, an embedded system such as a system inwhich electronic equipment with a display is mounted in a kiosk orautomobile, a wireless internet-connected voice-controlled speaker, ahome entertainment device, a remote control device, a gaming controller,a peripheral user input device, a wireless base station or access point,equipment that implements the functionality of two or more of thesedevices, or other electronic equipment.

As shown in the functional block diagram of FIG. 1 , device 10 mayinclude components located on or within an electronic device housingsuch as housing 12. Housing 12, which may sometimes be referred to as acase, may be formed of plastic, glass, ceramics, fiber composites, metal(e.g., stainless steel, aluminum, metal alloys, etc.), other suitablematerials, or a combination of these materials. In some situations,parts or all of housing 12 may be formed from dielectric or otherlow-conductivity material (e.g., glass, ceramic, plastic, sapphire,etc.). In other situations, housing 12 or at least some of thestructures that make up housing 12 may be formed from metal elements.

Device 10 may include control circuitry 14. Control circuitry 14 mayinclude storage such as storage circuitry 20. Storage circuitry 20 mayinclude hard disk drive storage, nonvolatile memory (e.g., flash memoryor other electrically-programmable-read-only memory configured to form asolid-state drive), volatile memory (e.g., static or dynamicrandom-access-memory), etc. Storage circuitry 20 may include storagethat is integrated within device 10 and/or removable storage media.

Control circuitry 14 may include processing circuitry such as processingcircuitry 22. Processing circuitry 22 may be used to control theoperation of device 10. Processing circuitry 22 may include on one ormore microprocessors, microcontrollers, digital signal processors, hostprocessors, baseband processor integrated circuits, application specificintegrated circuits, central processing units (CPUs), graphicsprocessing units (GPUs), etc. Control circuitry 14 may be configured toperform operations in device 10 using hardware (e.g., dedicated hardwareor circuitry), firmware, and/or software. Software code for performingoperations in device 10 may be stored on storage circuitry 20 (e.g.,storage circuitry 20 may include non-transitory (tangible) computerreadable storage media that stores the software code). The software codemay sometimes be referred to as program instructions, software, data,instructions, or code. Software code stored on storage circuitry 20 maybe executed by processing circuitry 22. If desired, portions of storagecircuitry 20 may be located on processing circuitry 22 (e.g., as L1 andL2 cache), whereas other portions of storage circuitry 20 are locatedexternal to processing circuitry 22 (e.g., while remaining accessible toprocessing circuitry 22 via a memory interface).

Control circuitry 14 may be used to run software on device 10 such assatellite navigation applications, internet browsing applications,voice-over-internet-protocol (VOIP) telephone call applications, emailapplications, media playback applications, gaming applications,operating system functions, etc. To support interactions with externalequipment, control circuitry 14 may be used in implementingcommunications protocols. Communications protocols that may beimplemented using control circuitry 14 include internet protocols,wireless local area network (WLAN) protocols (e.g., IEEE 802.11protocols—sometimes referred to as Wi-Fi®), protocols for othershort-range wireless communications links such as the Bluetooth®protocol or other wireless personal area network (WPAN) protocols, IEEE802.11ad protocols (e.g., ultra-wideband protocols), cellular telephoneprotocols (e.g., 3G protocols, 4G (LTE) protocols, 3GPP Fifth Generation(5G) New Radio (NR) protocols, etc.), antenna diversity protocols,satellite navigation system protocols (e.g., global positioning system(GPS) protocols, global navigation satellite system (GLONASS) protocols,etc.), antenna-based spatial ranging protocols (e.g., radio detectionand ranging (RADAR) protocols or other desired range detection protocolsfor signals conveyed at millimeter and centimeter wave frequencies), orany other desired communications protocols. Each communications protocolmay be associated with a corresponding radio access technology (RAT)that specifies the physical connection methodology used in implementingthe protocol.

Device 10 may include input-output circuitry 16. Input-output circuitry16 may include input-output devices 18. Input-output devices 18 may beused to allow data to be supplied to device 10 and to allow data to beprovided from device 10 to external devices. Input-output devices 18 mayinclude user interface devices, data port devices, and otherinput-output components. For example, input-output devices 18 mayinclude touch sensors, displays (e.g., touch-sensitive and/orforce-sensitive displays), light-emitting components such as displayswithout touch sensor capabilities, buttons (mechanical, capacitive,optical, etc.), scrolling wheels, touch pads, key pads, keyboards,microphones, cameras, buttons, speakers, status indicators, audio jacksand other audio port components, digital data port devices, motionsensors (accelerometers, gyroscopes, and/or compasses that detectmotion), capacitance sensors, proximity sensors, magnetic sensors, forcesensors (e.g., force sensors coupled to a display to detect pressureapplied to the display), etc. In some configurations, keyboards,headphones, displays, pointing devices such as trackpads, mice, andjoysticks, and other input-output devices may be coupled to device 10using wired or wireless connections (e.g., some of input-output devices18 may be peripherals that are coupled to a main processing unit orother portion of device 10 via a wired or wireless link).

Input-output circuitry 16 may include wireless circuitry 24 to supportwireless communications. Wireless circuitry 24 (sometimes referred toherein as wireless communications circuitry 24) may include one or moreantennas 30. Wireless circuitry 24 may also include baseband processorcircuitry, transceiver circuitry, amplifier circuitry, filter circuitry,switching circuitry, radio-frequency transmission lines, and/or anyother circuitry for transmitting and/or receiving radio-frequencysignals using antennas 30. While control circuitry 14 is shownseparately from wireless circuitry 24 in the example of FIG. 1 for thesake of clarity, wireless circuitry 24 may include processing circuitrythat forms a part of processing circuitry 22 and/or storage circuitrythat forms a part of storage circuitry 20 of control circuitry 14 (e.g.,portions of control circuitry 14 may be implemented on wirelesscircuitry 24). As an example, control circuitry 14 may include basebandprocessor circuitry or other control components that form a part ofwireless circuitry 24. The baseband processor circuitry may, forexample, access a communication protocol stack on control circuitry 14(e.g., storage circuitry 20) to: perform user plane functions at a PHYlayer, MAC layer, RLC layer, PDCP layer, SDAP layer, and/or PDU layer,and/or to perform control plane functions at the PHY layer, MAC layer,RLC layer, PDCP layer, RRC, layer, and/or non-access stratum layer. Ifdesired, the PHY layer operations may additionally or alternatively beperformed by radio-frequency (RF) interface circuitry in wirelesscircuitry 24.

Radio-frequency signals may be conveyed by wireless circuitry 24 using3GPP 5G New Radio (5G NR) communications bands or any other desiredcommunications bands (sometimes referred to herein as frequency bands orsimply as bands). The radio-frequency signals may include millimeterwave signals, sometimes referred to as extremely high frequency (EHF)signals, which propagate at frequencies above about 30 GHz (e.g., at 60GHz or other frequencies between about 30 GHz and 300 GHz). Theradio-frequency signals may also additionally or alternatively includecentimeter wave signals, which propagate at frequencies between about 10GHz and 30 GHz. The radio-frequency signals may additionally oralternatively include signals at frequencies less than 10 GHz, such assignals between about 410 MHz and 7125 MHz. In scenarios where theradio-frequency signals are conveyed using 5G NR communications bands,the radio-frequency signals may be conveyed in 5G NR communicationsbands within 5G NR Frequency Range 2 (FR2), which includes centimeterand millimeter wave frequencies between about 24 GHz and 100 GHz, 5G NRcommunications bands within 5G NR Frequency Range 1 (FR1), whichincludes frequencies below 7125 MHz, and/or other 5G NR communicationsbands within other 5G NR frequency ranges FRx (e.g., where x is aninteger greater than 2), which may include frequencies above around57-60 GHz. If desired, device 10 may also contain antennas for handlingsatellite navigation system signals, cellular telephone signals (e.g.,radio-frequency signals conveyed using long term evolution (LTE)communications bands or other non-5G NR communications bands), wirelesslocal area network signals, near-field communications, light-basedwireless communications, or other wireless communications.

For example, as shown in FIG. 1 , wireless circuitry 24 may includeradio-frequency transceiver circuitry that is used in conveyingradio-frequency signals using the 5G NR communications protocol and RATsuch as 5G NR transceiver circuitry 28. 5G NR transceiver circuitry 28may support communications at frequencies between about 24 GHz and 100GHz (e.g., within FR2, FRx, etc.) and/or at frequencies between about410 MHz and 7125 MHz (e.g., within FR1). Examples of frequency bandsthat may be covered by 5G NR transceiver circuitry 28 includecommunications bands under the family of 3GPP wireless communicationsstandards, communications bands under the IEEE 802.XX family ofstandards, an IEEE K communications band between about 18 GHz and 27GHz, a K_(a) communications band between about 26.5 GHz and 40 GHz, aK_(u) communications band between about 12 GHz and 18 GHz, a Vcommunications band between about 40 GHz and 75 GHz, a W communicationsband between about 75 GHz and 110 GHz, and/or other frequency bandsbetween approximately 10 GHz and 110 GHz, a C-band between about 3300MHz and 5000 MHz, an S-band between about 2300 MHz and 2400 MHz, anL-band between about 1432 MHz and 1517 MHz, and/or other frequency bandsbetween approximately 410 MHz and 7125 MHz. 5G NR transceiver circuitry28 may be formed from one or more integrated circuits (e.g., multipleintegrated circuits mounted on a common printed circuit in asystem-in-package or system-on-chip device, one or more integratedcircuits mounted on different substrates, etc.). Wireless circuitry 24may cover different frequency bands that are used in differentgeographic regions if desired.

Wireless communications using 5G NR transceiver circuitry 28 may bebidirectional. For example, 5G NR transceiver circuitry 28 may conveyradio-frequency signals 36 to and from external wireless equipment suchas external equipment 8. External equipment 8 may be another electronicdevice such as electronic device 10, may be a wireless access point, maybe a wireless base station, etc. Implementations in which externalequipment 8 is a wireless base station are sometimes described herein asan example. External equipment 8 may therefore sometimes be referred toherein as wireless base station 8 or simply as base station 8. Basestation 8 may have control circuitry such as control circuitry 14 andwireless circuitry such as wireless circuitry 24 of device 10. Thecontrol circuitry on base station 8 and/or other portions of network 6(e.g., control circuitry running on other base stations, cloud networks,virtual or logical networks, physical networks, wired networks, wirelessnetworks, local area networks, servers, network nodes, routers,terminals, computing devices, switches, and/or any other desiredcomponents of network 6) may store, maintain, operate, update, process,and/or implement a network scheduler for base station 8. The networkscheduler may be implemented using software and/or hardware running onnetwork 6. The network scheduler may generate network (communications)schedules for each UE device in the cell of base station 8. The networkschedules may identify (assign) time and/or frequency domain resourcesfor use by each of the UE devices in communicating with base station 8(e.g., under the 5G NR protocol). The network scheduler may include anuplink scheduler that schedules uplink resources and a downlinkscheduler that schedulers downlink resources. In this way, the networkscheduler may coordinate communications resources to allow base station8 to provide satisfactory wireless communications and connectivity foreach of the UE devices in its cell.

Device 10 and base station 8 may form part (e.g., nodes and/orterminals) of a wireless communications network such as communicationsnetwork 6. Communications network 6 (sometimes referred to herein asnetwork 6) may include any desired number of devices 10, base stations8, and/or other network components (e.g., switches, routers, accesspoints, servers, end hosts, local area networks, wireless local areanetworks, etc.) arranged in any desired network configuration. Network 6may be managed by a wireless network service provider. Device 10 mayalso sometimes be referred to herein as user equipment (UE) 10 or UEdevice 10 (e.g., because device 10 may be used by an end user to performwireless communications with the network). Base station 8 may operatewithin a corresponding cell that spans a particular geographic locationor region. Base station 8 may be used to provide communicationscapabilities (e.g., 3GPP 5G NR communications capabilities) for multipleUE devices such as device 10 that are located within its cell. The airinterfaces over which the UEs devices and base station 8 communicate maybe compatible with 3GPP technical specifications (TSs) such as thosethat define 5G NR system standards.

Radio-frequency signals 36 (sometimes referred to herein as wirelesslink 36) may include radio-frequency signals transmitted by device 10 tobase station 8 (e.g., in uplink direction 32) and radio-frequencysignals transmitted by base station 8 to device 10 (e.g., in downlinkdirection 34). The radio-frequency signals 36 conveyed in uplinkdirection 32 may sometimes be referred to herein as uplink (UL) signals.The radio-frequency signals in downlink direction 34 may sometimes bereferred to herein as downlink (DL) signals. Radio-frequency signals 36may be used to convey wireless data. The wireless data may include astream of data arranged into data packets, symbols, frames, etc. Thewireless data may be organized/formatted according to the communicationsprotocol governing the wireless link between device 10 and base station8 (e.g., a 5G NR communications protocol). Wireless data conveyed by theuplink signals transmitted by device 10 (e.g., in uplink direction 32)may sometimes be referred to herein as uplink data. Wireless dataconveyed by the downlink signals transmitted by base station 8 in (e.g.,in downlink direction 34) may sometimes be referred to herein asdownlink data. The wireless data may, for example, include data that hasbeen encoded into corresponding data packets such as wireless dataassociated with a telephone call, streaming media content, internetbrowsing, wireless data associated with software applications running ondevice 10, email messages, etc. Control signals may also be conveyed inthe uplink and/or downlink direction between base station 8 and device10.

If desired, wireless circuitry 24 may also include transceiver circuitryfor handling communications in non-5G NR communications bands such asnon-5G NR transceiver circuitry 26. Non-5G NR transceiver circuitry 26may include wireless local area network (WLAN) transceiver circuitrythat handles 2.4 GHz and 5 GHz bands for Wi-Fi® (IEEE 802.11)communications, wireless personal area network (WPAN) transceivercircuitry that handles the 2.4 GHz Bluetooth® communications band,cellular telephone transceiver circuitry that handles cellular telephonecommunications bands from 700 to 960 MHz, 1710 to 2170 MHz, 2300 to 2700MHz, and/or or any other desired cellular telephone communications bandsbetween 600 MHz and 4000 MHz (e.g., cellular telephone signals conveyedusing a 4G LTE protocol, a 3G protocol, or other non-5G NR protocols),GPS receiver circuitry that receives GPS signals at 1575 MHz or signalsfor handling other satellite positioning data (e.g., GLONASS signals at1609 MHz, BeiDou Navigation Satellite System (BDS) band signals, etc.),television receiver circuitry, AM/FM radio receiver circuitry, pagingsystem transceiver circuitry, near field communications (NFC) circuitry,ultra-wideband (UWB) transceiver circuitry that operates under the IEEE802.15.4 protocol and/or other ultra-wideband communications protocols,etc. Non-5G NR transceiver circuitry 26 and 5G NR transceiver circuitry28 may each include one or more integrated circuits, power amplifiercircuitry, low-noise input amplifiers, passive radio-frequencycomponents, filters, synthesizers, modulators, demodulators, modems,mixers, switching circuitry, transmission line structures, and othercircuitry for handling radio-frequency signals. Non-5G NR transceivercircuitry 26 may transmit and receive radio-frequency signals below 10GHz (and organized according to a non-5G NR communications protocol)using one or more antennas 30. 5G NR transceiver circuitry 28 maytransmit and receive radio-frequency signals (e.g., at FR1 and/orFR2/FRx frequencies including frequencies above 57 GHz) using antennas30.

5G NR transceiver circuitry 28 may, for example, include basebandprocessor circuitry. The baseband processor circuitry mayprocess/generate baseband signals or waveforms that carry information in3GPP-compatible networks such as network 6. If desired, the waveformsmay be based on cyclic prefix orthogonal frequency-division multiplexing(CP-OFDM) in the uplink or downlink, and discrete Fourier transformspread OFDM (DFT-S-OFDM) in the uplink. 5G NR transceiver circuitry 28may also include upconverter and/or downconverter circuitry (e.g., mixercircuitry) for converting signals between baseband andradio-frequencies, between baseband and intermediate frequencies betweenbaseband and radio-frequencies, and/or between intermediate frequenciesand radio-frequencies.

In satellite navigation system links, cellular telephone links, andother long-range links, radio-frequency signals are typically used toconvey data over thousands of feet or miles. In Wi-Fi® and Bluetooth®links at 2.4 and 5 GHz and other short-range wireless links,radio-frequency signals are typically used to convey data over tens orhundreds of feet. 5G NR transceiver circuitry 28 may conveyradio-frequency signals over short distances that travel over aline-of-sight path. To enhance signal reception for 5G NRcommunications, and particularly for communications at frequenciesgreater than 10 GHz, phased antenna arrays and beam forming (steering)techniques may be used (e.g., schemes in which antenna signal phaseand/or magnitude for each antenna in an array are adjusted to performbeam steering). Antenna diversity schemes may also be used to ensurethat the antennas that have become blocked or that are otherwisedegraded due to the operating environment of device 10 can be switchedout of use and higher-performing antennas used in their place.

Antennas 30 in wireless circuitry 24 may be formed using any suitableantenna types. For example, antennas 30 may include antennas withresonating elements that are formed from stacked patch antennastructures, loop antenna structures, patch antenna structures,inverted-F antenna structures, slot antenna structures, planarinverted-F antenna structures, monopole antenna structures, dipoleantenna structures, helical antenna structures, Yagi (Yagi-Uda) antennastructures, hybrids of these designs, etc. If desired, one or more ofantennas 30 may be cavity-backed antennas. Different types of antennasmay be used for different bands and combinations of bands. For example,one type of antenna may be used in forming non-5G NR wireless links fornon-5G NR transceiver circuitry 26 and another type of antenna may beused in conveying radio-frequency signals in 5G NR communications bandsfor 5G NR transceiver circuitry 28. If desired, antennas 30 that areused to convey radio-frequency signals for 5G NR transceiver circuitry28 may be arranged in one or more phased antenna arrays.

FIG. 2 is a diagram showing how base station 8 may communicate withdevice 10 within a corresponding cell of network 6. As shown in FIG. 2 ,network 6 may be organized into one or more cells such as cell 40distributed across one or more geographic areas or regions. Cell 40 mayhave any desired shape (e.g., a hexagonal shape, a rectangular shape, acircular shape, an elliptical shape, or any other desired shape havingany desired number of straight and/or curved sides). Base station 8 maycommunicate with one or more UE devices within cell 40 such as device 10(e.g., to provide communications access for device 10 to the rest ofnetwork 6, other UE devices, other networks, the Internet, etc.). Whilethe storage and processing operations of base station 8 may sometimes bedescribed herein as being performed by or at base station 8, some or allof the control circuitry for base station 8 (e.g., storage circuitrysuch as storage circuitry 20 and/or processing circuitry such asprocessing circuitry 22) may be located at base station 8 and/or may bedistributed across two or more network devices in network 6 (e.g., anydesired number of base stations, servers, cloud networks, physicaldevices, distributed and/or virtual/logical devices implemented viasoftware, etc.).

When operating at relatively high frequencies such as frequenciesgreater than 10 GHz, the radio-frequency signals conveyed between basestation 8 and device 10 may be subject to substantial over-the-airsignal attenuation. In order to increase the gain of these signals, basestation 8 and/or device 10 may convey the radio-frequency signals usingphased antenna arrays (e.g., phased arrays of antennas 30). Each antennain the phased antenna array may convey radio-frequency signals that areprovided with a respective phase and magnitude. The signals conveyed byeach antenna constructively and destructively interfere to produce acorresponding signal beam having a pointing direction (e.g., thedirection of the signal beam having peak gain). The phases and/ormagnitudes provided to each antenna may be adjusted to actively steerthe signal beam in different directions.

For example, as shown in FIG. 2 , device 10 may use a phased antennaarray to convey radio-frequency signals (e.g., radio-frequency signals36 of FIG. 1 ) over signal beam 42. Device 10 may adjust thephases/magnitudes provided to each antenna in the phased antenna arrayto point signal beam 42 in a selected pointing direction (e.g., thedirection of peak gain), as shown by arrow 48. Similarly, base station 8may use a phased antenna array to convey radio-frequency signals oversignal beam 44. Base station 8 may adjust the phases/magnitudes providedto each antenna in the phased antenna array to steer signal beam 44 topoint in a selected pointing direction, as shown by arrow 46. Basestation 8 may steer signal beam 44 to point towards device 10 and device10 may steer signal beam 42 to point towards base station 8 to allowwireless data to be conveyed between base station 8 and device 10.Phased antenna arrays may also sometimes be referred to as phased arrayantennas (e.g., phased arrays of antenna elements). The signal beamdirections may be adjusted over time as device 10 moves relative to basestation 8. Handover operations may be performed with other base stationsin network 6 as device 10 moves between cells 40.

Device 10 may transmit uplink signals to base station 8 (sometimesreferred to herein as gNB 8) within signal beam 42. Device 10 maytransmit the uplink signals at a selected output power level (sometimesreferred to herein as an uplink output power level, transmission powerlevel, or transmit power level). Device 10 may have a maximum outputpower level P_(CMAX) (e.g., the maximum output power level with whichdevice 10 can transmit radio-frequency signals within signal beam 42).The output power level may be adjusted using an uplink (UL) powercontrol operation. In cellular networks, UL power control can be acomplicated process that includes an open loop power control operationduring initial access (e.g., during a physical random access channel(PRACH) process), followed by a closed loop power control operation whenthe UE device is in connection with the network (e.g., when the UE andthe base station convey physical uplink shared channel (PUSCH) signals,physical uplink control channel (PUCCH) signals, sounding referencesignals (SRS), etc.).

During radio-frequency signal transmission, some of the radio-frequencysignals transmitted by device 10 may be incident upon external objectssuch as external object 50. External object 50 may be, for example, thebody of the user of device 10 or another human or animal. Externalobject 50 may therefore sometimes be referred to herein as user 50. Inthese scenarios, the amount of radio-frequency energy exposure at user50 may be characterized by one or more radio-frequency (RF) exposuremetrics. The RF exposure metrics may include specific absorption rate(SAR) for radio-frequency signals at frequencies less than 6 GHz (inunits of W/kg), maximum permissible exposure (MPE) for radio-frequencysignals at frequencies greater than 6 GHz (in units of mW/cm²), andtotal exposure ratio (TER), which combines SAR and MPE. Regulatoryrequirements (e.g., as imposed by governmental, regulatory, or industrystandards or regulations for the region in which cell 40 is located)often impose limits on the amount of RF energy exposure permissible forexternal object 50 within the vicinity of the antennas on device 10 overa specified time period (e.g., SAR and MPE limits over a correspondingregulatory averaging period).

In general, the maximum radiated radio-frequency (RF) power allowedwhile maintaining compliance with regulatory requirements is a functionof the position of device 10 relative to user 50, the current directionof signal beam 42 (as well as sidelobe levels of signal beam 42; theprimary lobe of signal beam 42 is illustrated in FIG. 2 ), and theproximity of user 50 to the antennas on device 10 that produce signalbeam 42. The RF energy exposure (e.g., the SAR and MPE) produced bydevice 10 primarily depends on the transmit power level of device 10 andthe UL duty cycle of device 10. The transmit (uplink) power level ofdevice 10 is provided by amplifiers (e.g., power amplifiers) in thetransmit chain(s) of wireless circuitry 24 (FIG. 1 ). The duty cycle ofdevice 10 is given by the fraction of the time resources for device 10that are used for UL transmission (e.g., the fraction or percentage ofthe time slots in a given time period that the transmit chain(s) areactively transmitting radio-frequency signals).

In prior versions of the 3GPP TSSs, the power management term P-MPR(Power Management Maximum Power Reduction) is the only availableresource for device 10 to ensure compliance with regulatory requirementson RF energy exposure. The power management term P-MPR (sometimesreferred to herein as maximum power reduction MPR) in the 3GPP TSSsspecifies a reduction in the maximum transmit power level for device 10(e.g., so that subsequently-transmitted signals are transmitted atuplink power levels that are less than the maximum transmit power levelP_(CMAX) of device 10 minus the power reduction specified by the powermanagement term P-MPR). This reduction in maximum transmit power levellimits the amount of radio-frequency energy exposure for user 50adjacent to device 10, thereby helping to ensure that device 10satisfies the regulatory requirements on RF energy exposure.

However, performing RF exposure compliance in this way using onlytransmit power backoffs (maximum power reductions) can lead to reduceduplink coverage for device 10. For example, a transmit power backoff(MPR) of just 6 dB can result in a reduction in the uplink range ofdevice 10 (e.g., the distance with which device 10 can transmit uplinksignals that are received at base station 8 with satisfactory signalquality) of more than 30%. As another example, sudden and drasticreductions in UL transmit power through P-MPR (e.g., due to the suddendetected proximity of user 50 adjacent device 10 or within signal beam42) can lead to radio link failure (RLF) with base station 8.

On the other hand, in prior versions of the 3GPP TSSs, the maximum ULduty cycle for device 10 remains static and is merely reported by device10 to the network when device 10 transmits its UE capabilities to basestation 8 (e.g., using the maxUplinkDutyCycle-FR2 term). ThemaxUplinkDutyCycle-FR2 term is only a single static limit that does notconsider different use cases that can occur, and only defines a dutycycle limit at which device 10 will start applying transmit powerbackoffs (MPRs). When the maxUplinkDutyCycle-FR2 term is absent in theUE capabilities transmitted by device 10 to base station 8, then RFexposure requirements must be met using other means such as MPR. Inaddition, the maxUplinkDutyCycle-FR2 term does not allow for scaling theUL duty cycle dynamically to avoid transmit power backoffs in differentsituations. For example, the device can be located in differentpositions relative to the user's head or body, causing different amountsof RF energy exposure and consequently allowing for different UL dutycycle values while transmitting at a maximum transmit power level.

In addition, devices such as device 10 may apply sensing to detectwhether or not external objects (e.g., a portion of user 50 such as theuser's hand, finger, or head) are close to the device. The allowed levelof RF energy exposure depends on the sensing result (e.g., if an objectis close to the transmitting antenna(s) or not). Consequently, thedevice is required to scale the RF energy exposure accordingly, and suchscaling would need to be performed dynamically. ThemaxUplinkDutyCycle-FR2 term defined in the 3GPP TSSs does not allow forscaling of RF exposure, considering dynamic situations where objects arebeing detected by the sensor or moving out of the sensor detection area.In order to mitigate these issues associated with only using MPR and astatic maximum UL duty cycle, device 10 may dynamically adjust the ULduty cycle (e.g., the maximum UL duty cycle) used to transmit UL signalsto base station 8 to satisfy the regulatory requirements on RF energyexposure.

In order to allow device 10 to dynamically adjust UL duty cycle, device10 needs to rapidly coordinate with the network (e.g., base station 8)so the network can accommodate any changes (adjustments) to the UL dutycycle over time. If care is not taken, using a media access control(MAC) control element (CE) and radio resource control (RRC) interactionbetween device 10 and base station 8 can introduce an excessive amountof delay to the system. It may therefore be desirable to be able tocoordinate dynamic UL duty cycle adjustment outside of the MAC CE andRRC interaction where possible.

FIG. 3 is a flow chart of illustrative operations that may be performedby network 6 to perform and coordinate dynamic UL duty cycle adjustments(e.g., outside of the MAC CE and RRC interaction). Operations 52-58 ofFIG. 3 may be performed by device 10 while located in cell 40 for acorresponding base station 8. Operations 60-64 of FIG. 3 may beperformed by the base station 8 in the cell 30 where device 10 islocated.

At operation 52, device 10 may begin transmitting UL signals to basestation 8 using an initial maximum UL duty cycle. The uplinktransmissions may be performed according to a UL schedule generated bybase station 8 and/or other portions of network 6, which grants time ULslots to device 10 that implement the initial maximum UL duty cycle(e.g., after a wireless connection has already been established betweenbase station 8 and device 10). Base station 8 may begin receiving the ULsignals transmitted by device 10 using the initial maximum UL duty cycleat operation 92.

At operation 54, device 10 may perform proximity detection operations todetermine whether user 50 is at, adjacent, or proximate to the active(transmitting) antennas 30 on device 10 and/or signal beam 42. Theproximity detection operations help device 10 to determine whether user54 will be subject to RF energy exposure from signal beam 42, such thatdevice 10 will begin to accumulate SAR and/or MPE from the presence ofuser 54. Such communications may be subject to regulations on RF energyexposure (e.g., SAR limits and/or MPE limits).

Device 10 may perform proximity detection operations using one or moreimage sensors, one or more capacitive proximity sensors, one or morevoltage standing wave ratio (VSWR) sensors coupled to the activetransmit antennas on device 10 (e.g., sensors that measure the amount ofradio-frequency energy reflected from a transmit antenna back towardsthe transceiver due to the presence of external objects), one or moretouch sensors integrated into or separate from a display for device 10,one or more acoustic (e.g., ultrasonic) sensors, one or moreaccelerometers, one or more gyroscopes, one or more sensors that gatherwireless performance metric data such as receive signal strengthindicator (RSSI) values or signal-to-noise ratio (SNR) values,information indicating that user 50 is currently providing user input todevice 10, information indicating that user 50 is currently performingone or more software operations using software applications running ondevice 10, GPS data, one or more radar sensors, one or more lightdetection and ranging (Lidar) sensors, one or more infrared light orimage sensors, one or more ambient light sensors, and/or any otherdesired sensors on or coupled to device 10 that can detect the presenceof user 50 at, adjacent, or proximate to (e.g., within a thresholddistance from) one or more of the antennas on device 10. The proximitydetection operations may, if desired, distinguish between inanimateexternal objects and animate external objects (e.g., portions of thebody of user 50).

When device 10 detects the presence of user 50 at, adjacent, orproximate to one or more of the antennas on device 10 (e.g., the activeantennas being used to form signal beam 42), processing may proceed tooperation 56. At operation 56, device 10 (e.g., 5G NR transceivercircuitry 28 and one or more antennas 30 of FIG. 1 ) may transmit anindicator to base station 8 that identifies that an RF exposure eventhas occurred at device 10 (e.g., an event in which device 10 will beginto accumulate SAR/MPE that is subject to regulatory limits on RF energyexposure). Device 10 may transmit the indicator as a single bit or astring (series) of bits that identifies that the RF exposure event hasoccurred. In the example of FIG. 3 , device 10 transmits the indicatorover a physical uplink control channel (PUCCH) (e.g., using PUCCHsignals). Device 10 may, for example, transmit the indicator within theuplink control information (UCI) carried on the PUCCH.

At operation 62, base station 8 may receive the indicator transmitted bydevice 10 over the PUCCH. In this way, device 10 may inform base station8 and network 6 that the device requires a reduction in its maximum ULduty cycle in order to comply with regulations on RF energy exposure inthe presence of user 50 (e.g., the indicator over PUCCH may serve as atrigger for the network to adjust the maximum UL duty cycle of device10). In response to receipt of the indicator, base station 8 and/orother portions of network 6 (e.g., the UL scheduler for base station 8)may identify an updated maximum UL duty cycle for device 10 that islower than the initial UL duty cycle. The updated maximum UL duty cyclemay, for example, be a maximum UL duty cycle that is supported by basestation 8 and that will allow base station 8 to continue to communicatewith device 10 while also accommodating communications with the other UEdevices in cell 40. Base station 8 and/or other portions of network 6may, for example, generate or update the UL schedule for device 10and/or the other UE devices in cell 40 to implement/accommodate theupdated maximum UL duty cycle to be used by device 10.

At operation 64, base station 8 (e.g., 5G NR transceiver circuitry andone or more of the antennas on base station 8) may transmit a feedbacksignal to device 10 (e.g., using DL resources that are allocated to theparticular device 10 that transmitted the indicator to base station 8 atoperation 56). The feedback signal may identify the updated maximum ULduty cycle to be used by device 10 (e.g., may identify an updated ULschedule or grant for device 10 to use that accommodates/implements theupdated maximum UL duty cycle). In the example of FIG. 3 , base station8 transmits the feedback signal over a physical downlink control channel(PDCCH) (e.g., using PDCCH signals). Base station 8 may, for example,transmit the feedback signal within the downlink control information(DCI) carried on the PDCCH (e.g., as a series or string of bits).

At operation 58, device 10 may receive the feedback signal from basestation 8 and may begin transmitting UL signals using the updatedmaximum UL duty cycle (e.g., implementing the updated UL schedule orgrant generated by base station 8 and/or network 6). Device 10 maycontinue uplink communications using the updated maximum UL duty cyclewhile ensuring that any applicable regulations on RF energy exposure aresatisfied, because the updated maximum UL duty cycle is lower than theinitial maximum UL duty cycle and therefore produces less RF energyincident upon user 50. The updated maximum UL duty cycle may thereforesometimes be referred to herein as a reduced maximum UL duty cycle.Device 10 may continue to use the updated maximum UL duty cycle untiluser 50 is no longer detected at, adjacent, or proximate to thetransmitting antennas or signal beam 42, until base station 8 instructsdevice 10 to use a different maximum UL duty cycle, or until any otherdesired trigger condition occurs.

If desired, device 10 may suggest or request a particular updated ULduty cycle in response to detecting user 50 at, adjacent, or proximateto device 10, as shown in FIG. 4 . Operations 54, 66, 68, and 70 of FIG.4 may be performed by device 10. Operations 72-82 of FIG. 4 may beperformed by base station 8 and/or other portions of network 6.Operations 52 and 60 of FIG. 3 are also performed during the operationsof FIG. 4 but have been omitted from FIG. 4 for the sake of clarity.

Once device 10 has detected the presence of user 50 at operation 54,processing may then proceed to operation 66 of FIG. 4 . At operation 66,control circuitry 14 on device 10 may identify a new maximum UL dutycycle for use during subsequent communications that is less than theinitial maximum UL duty cycle. The new maximum UL duty cycle maysometimes be referred to herein as a suggested or requested maximum ULduty cycle. The new maximum UL duty cycle may be a maximum UL duty cyclethat would be sufficiently low so as to allow device 10 to continue totransmit UL signals (e.g., using the new maximum UL duty cycle) whilestill satisfying regulatory limits on MPE/SAR despite the presence ofuser 50.

At operation 68, device 10 (e.g., 5G NR transceiver circuitry 28 and oneor more antennas 30 of FIG. 1 ) may transmit an indicator to basestation 8 that identifies the new maximum UL duty cycle. The indicatormay include a single bit or a string (series) of bits that identifiesthat the new maximum UL duty cycle. In the example of FIG. 4 , device 10transmits the indicator over the physical uplink control channel (PUCCH)(e.g., using PUCCH signals). Device 10 may, for example, transmit theindicator within the uplink control information (UCI) carried on thePUCCH.

At operation 62, base station 8 may receive the indicator transmitted bydevice 10 over the PUCCH. In this way, device 10 may inform base station8 and network 6 that the device requires a reduction in its maximum ULduty cycle as well as a reduced maximum UL duty cycle that would allowdevice 10 to continue to comply with regulations on RF energy exposurein the presence of user 50. In response to receipt of the indicator,base station 8 and/or other portions of network 6 (e.g., the ULscheduler for base station 8) may process the new maximum UL duty cycleidentified by the indicator to determine whether use of the new maximumUL duty cycle for device 10 would be satisfactory for the network (e.g.,given the current traffic load on base station 8 from any other UEdevices in cell 40, load balancing policies for base station 8, etc.).

If the new maximum UL duty cycle identified by device 10 isunsatisfactory to network 6, processing may proceed to operation 76 viapath 74. At operation 76, base station 8 and/or other portions ofnetwork 6 may identify an updated maximum UL duty cycle for device 10that is lower than the initial UL duty cycle (e.g., that is supported bybase station 8 and that will allow base station 8 to continue tocommunicate with device 10 while also accommodating communications withthe other UE devices in cell 40). Base station 8 and/or other portionsof network 6 may, for example, generate or update the UL schedule fordevice 10 and/or the other UE devices in cell 40 toimplement/accommodate the updated maximum UL duty cycle to be used bydevice 10.

If the new maximum UL duty cycle identified by device 10 is satisfactoryto network 6, processing may proceed from operation 72 to operation 80via path 78. At operation 80, base station 8 and/or other portions ofnetwork 6 may set the new maximum UL duty cycle identified by device 10as the updated maximum UL duty cycle (e.g., base station 8 mayaccept/acknowledge the new maximum UL duty cycle suggested by device 10to allow device 10 to continue to satisfy SAR/MPE limits).

At operation 82, base station 8 may transmit a feedback signal to device10 (e.g., using DL resources that are allocated to the particular device10 that transmitted the indicator to base station 8 at operation 56).The feedback signal may identify the updated maximum UL duty cycle to beused by device 10. For example, base station 8 may acknowledge to device10 that the new maximum UL duty cycle as identified by device 10operation 66 has been accepted by the network for subsequent use bydevice 10 (e.g., using a single bit in the feedback signal) or mayinform device 10 of a different maximum UL duty cycle to use asidentified by base station 8 at operation 76 (e.g., using a series ofbits in the feedback signal). In the example of FIG. 4 , base station 8transmits the feedback signal over a physical downlink control channel(PDCCH) (e.g., using PDCCH signals). Base station 8 may, for example,transmit the feedback signal within the downlink control information(DCI) carried on the PDCCH.

At operation 70, device 10 may receive the feedback signal from basestation 8 and may begin transmitting UL signals using the updatedmaximum UL duty cycle (e.g., based on the updated UL schedule generatedby base station 8 and/or network 6). Device 10 may continue uplinkcommunications using the updated maximum UL duty cycle while ensuringthat any applicable regulations on RF energy exposure are satisfied,because the updated maximum UL duty cycle is lower than the initialmaximum UL duty cycle and therefore involves less RF energy beingincident upon user 50. Device 10 may continue to use the updated maximumUL duty cycle until user 50 is no longer detected at, adjacent, orproximate to the transmitting antennas or signal beam 42, until basestation 8 instructs device 10 to use a different maximum UL duty cycle,or until any other desired trigger condition occurs.

The examples of FIGS. 3 and 4 in which PUCCH/PDCCH are used by device 10and base station 8 to coordinate dynamic adjustment to the maximum ULduty cycle used by device 10 are merely illustrative. If desired, theinitial access process for device 10 and base station 8 may be used tocoordinate dynamic adjustment to the maximum UL duty cycle used bydevice 10. For example, device 10 and base station 8 may use the randomaccess channel (RACH) process to coordinate dynamic adjustment to themaximum UL duty cycle used by device 10.

FIG. 5 is a flow chart of illustrative operations involved in using theRACH process to coordinate dynamic adjustment to the maximum UL dutycycle used by device 10. Operations 84-90 of FIG. 5 may be performed bydevice 10 while located in cell 40 for a corresponding base station 8.Operations 92-96 of FIG. 5 may be performed by the base station 8 in thecell 40 where device 10 is located.

At operation 84, device 10 may begin transmitting UL signals to basestation 8 using an initial maximum UL duty cycle. Base station 8 maybegin receiving the UL signals transmitted by device 10 using theinitial maximum UL duty cycle at operation 92. Operations 84 and 92 mayoccur before device 10 has fully accessed and synchronized with network6, for example. Alternatively, operations 84 and 92 may be omitted ifdesired.

At operation 86, device 10 may perform proximity detection operations todetermine whether user 50 is at, adjacent, or proximate to the active(transmitting) antennas 30 on device 10 and/or signal beam 42. Theproximity detection operations may include the same proximity detectionoperations as performed at operation 54 of FIGS. 3 and 4 , for example.

When device 10 detects the presence of user 50 at, adjacent, orproximate to one or more of the antennas on device 10 (e.g., the activeantennas being used to form signal beam 42), processing may proceed tooperation 88. At operation 88, device 10 (e.g., 5G NR transceivercircuitry 28 and one or more antennas 30 of FIG. 1 ) may transmit anindicator to base station 8 that identifies that an RF exposure eventhas occurred at device 10 (e.g., an event in which device 10 will beginto accumulate SAR/MPE that is subject to regulatory limits on RF energyexposure). In the example of FIG. 5 , device 10 transmits the indicatorover a physical random access channel (PRACH) (e.g., using PRACHsignals). In other words, the indicator transmitted by device 10 may becarried on the PRACH. Device 10 may transmit the indicator as a singlebit or a string (series) of bits that identifies that the RF exposureevent has occurred (e.g., within a PRACH preamble).

At operation 94, base station 8 may receive the indicator transmitted bydevice 10 over the PRACH. In this way, device 10 may inform base station8 and network 6 that the device requires a reduction in its maximum ULduty cycle in order to comply with regulations on RF energy exposure inthe presence of user 50. In response to receipt of the indicator, basestation 8 and/or other portions of network 6 (e.g., the UL scheduler forbase station 8) may identify an updated maximum UL duty cycle for device10 that is lower than the initial UL duty cycle. The updated maximum ULduty cycle may, for example, be a maximum UL duty cycle that issupported by base station 8 and that will allow base station 8 tocontinue to communicate with device 10 while also accommodatingcommunications with the other UE devices in cell 40. Base station 8and/or other portions of network 6 may, for example, generate or updatethe UL schedule for device 10 and/or the other UE devices in cell 40 toimplement/accommodate the updated maximum UL duty cycle to be used bydevice 10.

At operation 96, base station 8 may transmit a feedback signal to device10 (e.g., to the specific device 10 that transmitted the indicator). Thefeedback signal may identify the updated maximum UL duty cycle to beused by device 10 (e.g., may identify an updated UL schedule or grantfor device 10 that accommodates/implements the updated maximum UL dutycycle). In the example of FIG. 5 , base station 8 transmits the feedbacksignal using a random access response (RAR) (e.g., a Msg2 RAR). In otherwords, the feedback signal (e.g., information identifying the updatedmaximum UL duty cycle) may be carried on a RAR.

At operation 90, device 10 may receive the feedback signal from basestation 8 and may begin transmitting UL signals using the updatedmaximum UL duty cycle (e.g., implementing the updated UL schedule orgrant generated by base station 8 and/or network 6). Device 10 maycontinue uplink communications using the updated maximum UL duty cyclewhile ensuring that any applicable regulations on RF energy exposure aresatisfied, because the updated maximum UL duty cycle is lower than theinitial maximum UL duty cycle and therefore involves less RF energybeing incident upon user 50. The updated maximum UL duty cycle maytherefore sometimes be referred to herein as a reduced maximum UL dutycycle. Device 10 may continue to use the updated maximum UL duty cycleuntil user 50 is no longer detected at, adjacent, or proximate to thetransmitting antennas or signal beam 42, until base station 8 instructsdevice 10 to use a different maximum UL duty cycle, or until any otherdesired trigger condition occurs.

If desired, device 10 may suggest or request a particular updated ULduty cycle in response to detecting user 50 at, adjacent, or proximateto device 10, as shown in FIG. 6 . Operations 86 and 100-104 of FIG. 6may be performed by device 10. Operations 106-116 of FIG. 6 may beperformed by base station 8 and/or other portions of network 6.

Once device 10 has detected the presence of user 50 at operation 86,processing may then proceed to operation 100 of FIG. 6 . At operation86, control circuitry 14 on device 10 may identify a new maximum UL dutycycle for use during subsequent communications that is less than theinitial maximum UL duty cycle. The new maximum UL duty cycle maysometimes be referred to herein as a suggested or requested maximum ULduty cycle. The new maximum UL duty cycle may be a maximum UL duty cyclethat would be sufficiently low so as to allow device 10 to continue totransmit UL signals (e.g., using the new maximum UL duty cycle) whilestill satisfying regulatory limits on MPE/SAR despite the presence ofuser 50.

At operation 102, device 10 (e.g., 5G NR transceiver circuitry 28 andone or more antennas 30 of FIG. 1 ) may transmit an indicator to basestation 8 that identifies the new maximum UL duty cycle. The indicatormay include a single bit or a string (series) of bits that identifiesthat the new maximum UL duty cycle. In the example of FIG. 6 , device 10transmits the indicator over a physical random access channel (PRACH)(e.g., using PRACH signals). In other words, the indicator transmittedby device 10 may be carried on the PRACH.

At operation 106, base station 8 may receive the indicator transmittedby device 10 over the PRACH. In this way, device 10 may inform basestation 8 and network 6 that the device requires a reduction in itsmaximum UL duty cycle as well as a reduced maximum UL duty cycle thatwould allow device 10 to continue to comply with regulations on RFenergy exposure in the presence of user 50. In response to receipt ofthe indicator, base station 8 and/or other portions of network 6 (e.g.,the UL scheduler for base station 8) may process the new maximum UL dutycycle identified by the indicator to determine whether the use of thenew maximum UL duty cycle for device 10 would be satisfactory for thenetwork (e.g., without unfairly interfering with the current trafficload on base station 8 from other UE devices in cell 40, based on theload balancing policies for base station 8, etc.).

If the new maximum UL duty cycle identified by device 10 isunsatisfactory to network 6, processing may proceed to operation 110 viapath 108. At operation 110, base station 8 and/or other portions ofnetwork 6 may identify an updated maximum UL duty cycle for device 10that is lower than the initial UL duty cycle (e.g., that is supported bybase station 8 and that will allow base station 8 to continue tocommunicate with device 10 while also accommodating communications withthe other UE devices in cell 40). Base station 8 and/or other portionsof network 6 may, for example, generate or update the UL schedule fordevice 10 and/or the other UE devices in cell 40 toimplement/accommodate the updated maximum UL duty cycle to be used bydevice 10.

If the new maximum UL duty cycle identified by device 10 is satisfactoryto network 6, processing may proceed from operation 106 to operation 114via path 112. At operation 114, base station 8 and/or other portions ofnetwork 6 may set the new maximum UL duty cycle identified by device 10as the updated maximum UL duty cycle (e.g., base station 8 mayaccept/acknowledge the new maximum UL duty cycle suggested by device 10to allow device 10 to continue to satisfy SAR/MPE limits).

At operation 116, base station 8 may transmit a feedback signal todevice 10. The feedback signal may identify the updated maximum UL dutycycle to be used by device 10. In the example of FIG. 6 , base station 8transmits the feedback signal using a random access response (RAR)(e.g., a Msg2 RAR). In other words, the feedback signal (e.g.,information identifying the updated maximum UL duty cycle) may becarried on a RAR. For example, base station 8 may acknowledge to device10 that the new maximum UL duty cycle as identified by device 10operation 100 has been accepted by the network for subsequent use bydevice 10 (e.g., using a single bit in the RAR message) or may informdevice 10 of a different maximum UL duty cycle to use as identified bybase station 8 at operation 110 (e.g., using a series of bits in the RARmessage).

At operation 104, device 10 may receive the feedback signal from basestation 8 and may begin transmitting UL signals using the updatedmaximum UL duty cycle (e.g., according to the updated UL schedulegenerated by base station 8 and/or network 6). Device 10 may continueuplink communications using the updated maximum UL duty cycle whileensuring that any applicable regulations on RF energy exposure aresatisfied, because the updated maximum UL duty cycle is lower than theinitial maximum UL duty cycle and therefore involves less RF energybeing incident upon user 50. Device 10 may continue to use the updatedmaximum UL duty cycle until user 50 is no longer detected at, adjacent,or proximate to the transmitting antennas or signal beam 42, until basestation 8 instructs device 10 to use a different maximum UL duty cycle,or until any other desired trigger condition occurs.

If desired, device 10 may perform dynamic scaling of the maximum UL dutycycle to maintain RF exposure within regulatory limits (e.g., withoutusing MPR). Device 10 may, for example, calculate the level of RFexposure that is caused by device 10. This calculation may considersensor data gathered by sensor(s) on device 10 (e.g., in input-outputdevices 18 of FIG. 1 ) indicative of the presence of user 50 or anotherexternal object nearby to the transmit antenna(s) on the device. Thecalculated level of RF exposure may include an absolute value and arelative value compared to the regulatory RF exposure limit.

FIG. 7 is a diagram showing how wireless circuitry 24 on device 10 mayinclude components for dynamically scaling of the maximum UL duty cycleto maintain RF exposure within regulatory limits. As shown in FIG. 7 ,wireless circuitry 24 may include maximum UL duty cycle calculationcircuitry 136, RF exposure (RFE) level calculation circuitry 132, and RFexposure limit (rule) database 134. These components may be implementedin hardware (e.g., one or more processors, circuit components, logicgates, diodes, transistors, switches, arithmetic logic units (ALUs),registers, application-specific integrated circuits, field-programmablegate arrays, etc.) and/or software on device 10. Maximum UL dutycalculation circuitry 136 may sometimes also be referred to herein asmaximum UL duty cycle calculation engine 136 or maximum UL duty cyclecalculator 136. RFE level calculation circuitry 132 may sometimes alsobe referred to herein as RFE level calculation engine 132 or RFE levelcalculator 132.

RF exposure limit database 134 may be coupled to maximum UL duty cyclecalculation circuitry 136 and RFE level calculation circuitry 132 overcontrol path 138. Maximum UL duty cycle calculation circuitry 136 mayhave an output coupled to 5G NR transceiver circuitry 28 (or othertransceiver circuitry in device 10) over control path 130. RFE levelcalculation circuitry 132 may have a first output coupled to 5G NRtransceiver circuitry 28 (or other transceiver circuitry in device 10)over control path 128 and may have a second output coupled to maximum ULduty cycle calculation circuitry 136 over control path 140. 5G NRtransceiver circuitry 28 may be coupled to antenna(s) 30 overradio-frequency transmission line path(s) 124.

During UL transmission, 5G NR transceiver circuitry 28 may transmituplink signals UL_SIG over radio-frequency transmission line path(s) 124and antenna(s) 30 (e.g., using a selected/current UL duty cycleULDC_CURR that is less than or equal to a current (e.g., initial)maximum UL duty cycle). Antenna(s) 30 may transmit uplink signals UL_SIGto base station 8 (e.g., over wireless link 36). As shown in FIG. 7 ,base station 8 may include antenna(s) 118, transceiver circuitry 120,and UL scheduler 122. This example is merely illustrative and, ifdesired, UL scheduler 122 may be located or distributed on otherportions of network 6. Antenna(s) 118 may also transmit DL signals toantenna(s) 30 on device 10 (e.g., over wireless link 36). Antenna(s) 30may pass the received DL signals to 5G NR transceiver circuitry 28 overradio-frequency transmission line path(s) 124.

RF exposure limit database 134 may be hard-coded or soft-coded intodevice 10 (e.g., in storage circuitry 16 of FIG. 1 ) and may include adatabase, data table, or any other desired data structure. RF exposurelimit database 134 may store RF exposure rules associated with theoperation of wireless circuitry 24 within different geographic regions.RF exposure limit database 134 may, for example, store regulatory SARlimits, regulatory MPE limits, and averaging periods for the SAR limitsand MPE limits (sometimes collectively referred to herein as RF exposurelimits RFE_LIMIT) for one or more geographic regions (e.g., countries,continents, states, localities, municipalities, provinces,sovereignties, etc.) that impose regulatory limits on the amount of RFenergy exposure permissible user 50 within the vicinity of antenna(s)30. As an example, RF exposure limit database 134 may store a first RFexposure limit RFE_LIMIT (e.g., a first SAR limit, a first MPE limit,and/or a first averaging period) imposed by the regulatory requirementsof a first country, a second RF exposure limit RFE_LIMIT (e.g., a secondSAR limit, a second MPE limit, and/or a second averaging period) imposedby the regulatory requirements of a second country, etc. The entries ofRF exposure limit database 134 may be stored upon manufacture, assembly,testing, and/or calibration of device 10 and/or may be updated duringthe operation of device 10 over time (e.g., periodically or in responseto a trigger condition such as a software update or the detection thatdevice 10 has entered a new country for the first time).

If desired, RF exposure limit database 134 may receive a control signalDEV_LOC (e.g., from other portions of control circuitry 14 of FIG. 1 )that identifies the current location of device 10. RF exposure limitdatabase 134 may use control signal DEV_LOC to identify the particularRF exposure limit RFE_LIMIT applicable to device 10 within cell 40(e.g., a particular averaging period, SAR limit, and/or MPE limitimposed by the corresponding regulatory body for the current location ofdevice 10). RF exposure limit database 134 may provide the identified RFexposure limit RFE_LIMIT to maximum UL duty cycle calculation circuitry136 and RFE level calculation circuitry 132 over control path 138.Control circuitry 14 may generate control signal DEV_LOC based on thecurrent GPS location of device 10, sensor data such as compass oraccelerometer data, a location of device 10 as identified by basestation 8 or an access point in communication with device 10, and/or anyother desired information indicative of the geographic location ofdevice 10. While RF exposure limit database 134 is sometimes describedherein as providing data to other components (e.g., maximum UL dutycycle calculation circuitry 136 and RFE level calculation circuitry132), one or more processors, memory controllers, or other componentsmay actively access the databases, may retrieve the stored data from thedatabase, and may pass the retrieved data to the other components forcorresponding processing.

RFE level calculation circuitry 132 may receive uplink informationUL_INFO from 5G NR transceiver circuitry 28 over control path 126.Uplink information UL_INFO may include information identifying thecurrent UL duty cycle ULDC_CURR used by 5G NR transceiver circuitry 28in transmitting uplink signals UL_SIG, information identifying themodulation scheme and/or modulation order used by 5G NR transceivercircuitry 28 in transmitting uplink signals UL_SIG, informationidentifying the transmit power level and/or maximum transmit power levelused by 5G NR transceiver circuitry 28 in transmitting uplink signalsUL_SIG, information identifying the frequency band(s) used by 5G NRtransceiver circuitry 28 in transmitting uplink signals UL_SIG, and/orany other desired information associated with the transmission of uplinksignals UL_SIG.

RFE level calculation circuitry 132 may also receive sensor data SENSover control path 126 (e.g., from 5G NR transceiver circuitry 28 or fromsensor(s) located elsewhere on device 10). Sensor data SENS may, forexample, be sensor data generated by one or more sensor(s) on device 10in performing proximity detection operations (e.g., at operations 54 ofFIGS. 3 and 4 and operations 86 of FIGS. 5 and 6 ). Sensor data SENS maytherefore be indicative of the presence or absence of a portion the bodyof user 50, whether device 10 is being held by the user, whether device10 is being held to the user's head, the distance between user 50 anddevice 10, etc.

RFE level calculation circuitry 132 may identify (e.g., generate,produce, calculate, deduce, derive, estimate, or compute) the currentamount of RF exposure CURR_RFE produced by 5G NR transceiver circuitry28 in transmitting uplink signals UL_SIG (e.g., over a correspondingaveraging period) based on the information contained within the uplinkinformation UL_INFO received from 5G NR transceiver circuitry 28 andbased on sensor data SENS. The current amount of RF exposure CURR_RFEmay depend on sensor data SENS (e.g., there may be more RF exposure whensensor data SENS indicates that user 50 is close to device 10, isholding device 10 to their head, etc. than when the sensor dataindicates that user 50 is far from device 10, is not holding device 10,etc.). RFE level calculation circuitry 132 may also generate (e.g.,identify, produce, calculate, deduce, derive, estimate, or compute) thecurrent RF exposure level RFE_LEVEL of 5G NR transceiver circuitry 28based on the current amount of RF exposure CURR_RFE and the RF exposurelimit RFE_LIMIT received from RF exposure limit database 134. Forexample, RFE level calculation circuitry 132 may generate RF exposurelevel RFE_LEVEL using equation 1.

$\begin{matrix}{{RFE\_ LEVEL} = {\frac{CURR\_ RFE}{RFE\_ LIMIT}*100\%}} & (1)\end{matrix}$

RFE level calculation circuitry 132 may, for example, include logic(e.g., digital logic) such as multipliers and dividers that generate RFexposure level RFE_LEVEL. RFE level calculation circuitry 132 may passRF exposure level RFE_LEVEL to 5G NR transceiver circuitry 28 overcontrol path 128. RFE level calculation circuitry 132 may also pass thecurrent uplink duty cycle ULDC_CURR from uplink information UL_INFO andthe current amount of RF exposure CURR_RFE to maximum UL duty cyclecalculation circuitry 136 over control path 140.

Maximum UL duty cycle calculation circuitry 136 may generate (e.g.,identify, produce, calculate, deduce, derive, estimate, or compute) anew (suggested/requested) maximum uplink duty cycle MAX_ULDC based onthe current uplink duty cycle ULDC_CURR (e.g., as received from RFElevel calculation circuitry 132), the current amount of RF exposureCURR_RFE received from RFE level calculation circuitry 132, and the RFexposure limit RFE_LIMIT received from RF exposure limit database 134.Maximum UL duty cycle calculation circuitry 136 may, for example,generate maximum uplink duty cycle MAX_ULDC using equation 2.

$\begin{matrix}{{MAX\_ ULDC} = {\frac{RFE\_ LIMIT}{CURR\_ RFE}*{ULDC\_ CURR}}} & (2)\end{matrix}$

Maximum UL duty cycle calculation circuitry 136 may, for example,include logic (e.g., digital logic) such as multipliers and dividersthat generate maximum uplink duty cycle MAX_ULDC. Maximum UL duty cyclecalculation circuitry 136 may pass maximum uplink duty cycle MAX_ULDC to5G NR transceiver circuitry 28 over control path 130. Maximum uplinkduty cycle MAX_ULDC may be a maximum uplink duty cycle that would allowdevice 10 to continue to perform UL transmission while satisfying theapplicable regulatory limits on RF exposure given the current amount ofRF exposure and the current UL duty cycle (e.g., without reducing themaximum transmit power level). Maximum UL duty cycle calculationcircuitry 136 may, for example, generate maximum uplink duty cycleMAX_ULDC while processing operation 66 of FIG. 4 or operation 100 ofFIG. 6 .

Additionally or alternatively, maximum UL duty cycle calculationcircuitry 136 may control (adjust) the UL duty cycle (e.g., the maximumuplink duty cycle) for other purposes, such as optimizing UL throughputfor different usage scenarios. The UL throughput depends on the UL dutycycle, the applied modulation scheme (e.g., a quadrature phase-shiftkeying (QPSK) modulation scheme, quadrature amplitude modulation (QAM)schemes such as 16-QAM, 64-QAM, or 256-QAM, etc.), and the transmitpower level. In scenarios where device 10 is relatively close to basestation 8, the highest throughput can be achieved using a relativelyhigh UL duty cycle and a relatively high modulation order, whereas onlya relatively low transmit power level is required. On the other hand, inscenarios where device 10 is relatively far from base station 8, device10 requires a relatively high transmit power level to close the link,whereas the highest UL throughput is achieved using a relatively low ULduty cycle and a relatively low modulation order such as QPSK (e.g.,reducing UL duty cycle can increase coverage and throughput in far cellscenarios).

For this reason, maximum UL duty cycle calculation circuitry 136 mayestimate the distance between device 10 and base station 8 within cell40. Maximum UL duty cycle calculation circuitry 136 may estimate thisdistance by measuring the signal strength of DL signals received frombase station 8 (e.g., RSSI values) and/or the pathloss associated withthe received DL signals (e.g., because greater distances are correlatedwith lower RSSI values and higher pathlosses). Maximum UL duty cyclecalculation circuitry 136 may then identify (e.g., produce, generate,compute, calculate, derive, deduce, etc.) an optimal uplink duty cycleOPT_ULDC (e.g., a path-loss optimized maximum uplink duty cycle) to usegiven the estimated distance or measured pathloss between device 10 andbase station 8. While optimal uplink duty cycle OPT_ULDC is sometimesreferred to herein as an optimal uplink duty cycle, optimal uplink dutycycle OPT_ULDC may be a maximum uplink duty cycle that has beenoptimized to account for the pathloss environment for device 10 incommunicating with base station 8, for example.

If desired, maximum UL duty cycle calculation circuitry 136 may store atable such as table 142 of FIG. 8 that correlates different measuredpathlosses PL with corresponding optimal UL duty cycles OPT_ULDC. Table142 may be hard-coded or soft-coded into device 10 and may beimplemented as a database, data table, or any other desired datastructure. The entries of table 142 may be stored upon manufacture,assembly, testing, and/or calibration of device 10 and/or may be updatedduring the operation of device 10 over time. As shown in FIG. 8 ,maximum UL duty cycle calculation circuitry 136 may store optimal uplinkduty cycles OPT_ULDC for each measured pathloss value PL (e.g., a firstoptimal uplink duty cycle OPT_ULDC to use when the measured pathloss hasvalue PL1, a second optimal uplink duty cycle OPT_ULDC to use when themeasured pathloss has value PL2, an Nth optimal uplink duty cycleOPT_ULDC to use when the measured pathloss has value PLN, etc.). MaximumUL duty cycle calculation circuitry 136 may identify the optimal uplinkduty cycle to use based on the measured pathloss PL (e.g., circuitry 136may identify that optimal uplink duty cycle OPT_ULDC1 should be usedwhen pathloss PL1 is measured, may identify that optimal uplink dutycycle OPT_ULDC2 should be used when pathloss PL2 is measured, etc.).

Once maximum UL duty cycle calculation circuitry 136 has identified theoptimal uplink duty cycle OPT_ULDC to use for the current measuredpathloss, maximum UL duty cycle calculation circuitry 136 may thentransmit the lower of maximum uplink duty cycle MAX_ULDC or optimaluplink duty cycle OPT_ULDC to 5G NR transceiver circuitry 28 overcontrol path 130. Transmitting maximum uplink duty cycle MAX_ULDC(sometimes referred to herein as the RFE-related UL duty cycle) to 5G NRtransceiver circuitry 28 when maximum uplink duty cycle MAX_ULDC islower than optimal uplink duty cycle OPT_ULDC may serve to ensure RFEcompliance for device 10. Transmitting optimal uplink duty cycleOPT_ULDC (sometimes referred to herein as the pathloss-related UL dutycycle or the pathloss-related maximum UL duty cycle) when optimal uplinkduty cycle OPT_ULDC is lower than maximum uplink duty cycle MAX_ULDC mayserve to maximize UL throughput.

5G NR transceiver circuitry 28 may transmit an uplink report UL_RPT tobase station 8 over radio-frequency transmission line path(s) 124 andantenna(s) 30. Uplink report UL_RPT may include the RF exposure levelRFE_LEVEL produced by RFE level calculation circuitry 132 and/or themaximum uplink duty cycle MAX_ULDC (or the optimal uplink duty cycleOPT_ULDC produced by maximum UL duty cycle calculation circuitry 136when OPT_ULDC is less than MAX_ULDC). For example, a reporting entity on5G NR transceiver circuitry 28 (e.g., within the baseband circuitry of5G NR transceiver circuitry 28) or elsewhere in wireless circuitry 24(e.g., interposed on control paths 128 and 130) may generate an uplinkreport UL_RPT containing information identifying RF exposure levelRFE_LEVEL and/or maximum uplink duty cycle MAX_ULDC (or optimal uplinkduty cycle OPT_ULDC) for transmission by antenna(s) 30 over wirelesslink 36. Uplink report UL_RPT may serve as a dynamic report to network 6that informs network 6 of the RF exposure level RFE_LEVEL produced atdevice 10 and/or the maximum uplink duty cycle MAX_ULDC (or optimaluplink duty cycle OPT_ULDC) that device 10 can afford for maintainingRFE compliance (e.g., given the current pathloss environment) withoutusing MPR.

FIG. 9 is a flow chart of illustrative operations that may be performedby wireless circuitry 24 on device 10 to generate uplink report UL_RPTfor transmission to base station 8 (e.g., for dynamically adjusting theUL duty cycle of device 10 over time or for otherwise ensuring thatdevice 10 is able to meet RFE requirements given its current RFE leveland pathloss environment).

At operation 144, control circuitry 14 (FIG. 1 ) may use RF exposurelimit database 134 to identify the RF exposure limit RFE_LIMIT (e.g., aSAR limit, MPE limit, and/or averaging period) imposed on device 10within cell 40 (e.g., based on control signal DEV_LOC). RF exposurelimit database 134 may pass RF exposure limit RFE_LIMIT to maximum ULduty cycle calculation circuitry 136 and RFE level calculation circuitry132 over control path 138.

At operation 146, 5G NR transceiver circuitry 28 may begin transmittinguplink signals UL_SIG over antenna(s) 30 using a current (maximum)uplink duty cycle ULDC_CURR. 5G NR transceiver circuitry 28 may generateuplink information UL_INFO and may transmit uplink information UL_INFOto RFE level calculation circuitry 132 over control path 126. Uplinkinformation UL_INFO may identify current uplink duty cycle ULDC_CURR andany other information used by RFE level calculation circuitry 132 toidentify the current amount of RF exposure CURR_RFE.

At operation 148, sensor(s) on device 10 may generate sensor data SENSand may provide sensor data SENS to RFE level calculation circuitry 132.Operations 144-148 may be performed in any desired sequence or, ifdesired, two or more (e.g., all) of operations 144-148 may be performedconcurrently (e.g., simultaneously) or in a time-interleaved manner.

At operation 150, RFE level calculation circuitry 132 may identify thecurrent amount of RF exposure CURR_RFE based on uplink informationUL_INFO and sensor data SENS. RFE level calculation circuitry 132 maythen generate RF exposure level RFE_LEVEL based on the current amount ofRF exposure CURR_RFE and RF exposure limit RFE_LIMIT (e.g., according toequation 1). RFE level calculation circuitry 132 may pass RF exposurelevel RFE_LEVEL to 5G NR transceiver circuitry 28 over control path 128.RFE level calculation circuitry 132 may pass the current (maximum)uplink duty cycle ULDC_CURR (e.g., as identified by uplink informationUL_INFO) and the current amount of RF exposure CURR_RFE to maximum ULduty cycle calculation circuitry 136 over control path 140.

At operation 152, maximum UL duty cycle calculation circuitry 136 maygenerate maximum uplink duty cycle MAX_ULDC based on RF exposure limitRFE_LIMIT, current (maximum) uplink duty cycle ULDC_CURR, and thecurrent amount of RF exposure CURR_RFE (e.g., according to equation 2).If desired, maximum UL duty cycle calculation circuitry 136 may alsoidentify (e.g., estimate, compute, derive, calculate, deduce, etc.) thepathloss between device 10 and base station 8 (e.g., using gathered RSSIvalues or other wireless performance metric values). Maximum UL dutycycle calculation circuitry 136 may then identify the optimal uplinkduty cycle OPT_ULDC corresponding to the estimated pathloss (e.g., usingtable 142 of FIG. 8 ). Maximum UL duty cycle calculation circuitry 136may compare optimal uplink duty cycle OPT_ULDC to maximum uplink dutycycle MAX_ULDC.

If maximum uplink duty cycle MAX_ULDC is less than or equal to optimaluplink duty cycle OPT_ULDC, processing may proceed from operation 152 tooperation 156 via path 154. At operation 156, maximum UL duty cyclecalculation circuitry 136 may pass the generated maximum uplink dutycycle MAX_ULDC to 5G NR transceiver circuitry 28 over control path 130.

At operation 158, 5G NR transceiver circuitry 28 may transmit an uplinkreport UL_RPT over antenna(s) 30 that includes information identifyingRF exposure level RFE_LEVEL (e.g., as generated by RFE level calculationcircuitry 132) and/or maximum uplink duty cycle MAX_ULDC for subsequentprocessing by base station 8 and/or other portions of network 6.

If optimal uplink duty cycle OPT_ULDC is less than maximum uplink dutycycle MAX_ULDC, processing may proceed from operation 152 to operation162 via path 160. At operation 162, maximum UL duty cycle calculationcircuitry 136 may pass the identified optimal uplink duty cycle OPT_ULDCto 5G NR transceiver circuitry 28 over control path 130.

At operation 164, 5G NR transceiver circuitry 28 may transmit an uplinkreport UL_RPT over antenna(s) 30 that includes information identifyingRF exposure level RFE_LEVEL (e.g., as generated by RFE level calculationcircuitry 132) and/or optimal uplink duty cycle OPT_ULDC for subsequentprocessing by base station 8 and/or other portions of network 6.

The example of FIG. 9 is merely illustrative. If desired, maximum ULduty cycle calculation circuitry 136 may forego identification ofoptimal uplink duty cycle OPT_ULDC. In these examples, the comparison atoperation 152 may be omitted and operations 162 and 164 may be omitted(e.g., processing may proceed directly from operation 152 to operation156). If desired, device 10 may transmit only RF exposure levelRFE_LEVEL within uplink report UL_RPT (e.g., without reporting MAX_ULDCor OPT_ULDC). In these examples, operations 152-164 may be omitted anddevice 10 may transmit uplink report UL_RPT at operation 150. Ifdesired, device 10 may transmit only MAX_ULDC or OPT_ULDC within uplinkreport UL_RPT (e.g., without reporting RFE_LEVEL).

If desired, 5G NR transceiver circuitry 28 may transmit uplink reportUL_RPT using MAC CE element signaling (e.g., MAC CE element signalingmay be extended to report RF exposure level RFE_LEVEL and/or maximumuplink duty cycle MAX_ULDC or optimal uplink duty cycle OPT_ULDC). Ifdesired, device 10 may transmit uplink report UL_RPT to base station 8once at the beginning of communications with base station 8 and may thentransmit subsequent uplink reports UL_RPT whenever the RF exposure levelRFE_LEVEL and/or maximum uplink duty cycle MAX_ULDC (or optimal uplinkduty cycle OPT_ULDC) change to a different value.

5G NR transceiver circuitry 28 may, for example, transmit uplink reportUL_RPT as indicator(s) within a MAC CE element. The indicator(s) mayinclude a first indicator identifying RF exposure level RFE_LEVEL and/ora second indicator identifying maximum UL duty cycle MAX_ULDC or optimalUL duty cycle OPT_ULDC. Each indicator may include, for example, asequence/series of bits. As one example, the first indicator may be a3-bit indicator. The second indicator may be a 3-bit indicator or a4-bit indicator. These examples are merely illustrative and, in general,each indicator may have any desired number of bits.

FIG. 10 shows a table 166 illustrating one example of how the firstindicator may be a 3-bit indicator for identifying different RF exposurelevels RFE_LEVEL to base station 8. As shown in FIG. 10 , the firstindicator may have a first value (e.g., “0”) when the RF exposure levelRFE_LEVEL is at a first value (e.g., when the RF exposure level is lessthan or equal to 25% relative to RF exposure limit RFE_LIMIT), a secondvalue (e.g., “1”) when RF exposure level RFE_LEVEL is at a second valuegreater than the first value (e.g., when the RF exposure level is 50%relative to RF exposure limit RFE_LIMIT), a third value (e.g., “2”) whenRF exposure level RFE_LEVEL is at a third value greater than the secondvalue (e.g., when the RF exposure level is at 75% relative to RFexposure limit RFE_LIMIT), a fourth value (e.g., “3”) when RF exposurelevel RFE_LEVEL is at a fourth value greater than the third value (e.g.,when the RF exposure level is at 100% relative to RF exposure limitRFE_LIMIT), a fifth value (e.g., “4”) when RF exposure level RFE_LEVELis at a fifth value greater than the fourth value (e.g., when the RFexposure level is at 150% relative to RF exposure limit RFE_LIMIT), asixth value (e.g., “5”) when RF exposure level RFE_LEVEL is at a sixthvalues greater than the fifth value (e.g., when the RF exposure level isat 200% relative to RF exposure limit RFE_LIMIT), a seventh value (e.g.,“6”) when RF exposure level RFE_LEVEL is at a seventh value greater thanthe sixth value (e.g., when the RF exposure level is at 300% relative toRF exposure limit RFE_LIMIT), or an eighth value (e.g., “7”) when RFexposure level RFE_LEVEL is at an eighth value greater than the seventhvalue (e.g., when the RF exposure level is greater than or equal to 400%relative to RF exposure limit RFE_LIMIT). This example is merelyillustrative and, in general, each value for the first indicator maycorrespond to any desired RF exposure levels RFE_LEVEL or may correspondto ranges of RF exposure levels RFE_LEVEL (e.g., where the RF exposurelevel RFE_LEVEL is rounded to the nearest value or the closest greatervalue in the second row of table 166). For example, if device 10generates an RFE_LEVEL of 55%, the MAC CE may be provided with a firstindicator value of “1” (which is the closest value in table 166 to 55%)or “2” (which is the closest greater value in table 166 to 55%).Rounding up to the closest greater value may allow device 10 withgreater confidence that RFE limits will be met, for example. In general,the first indicator may include any desired number of bits to report RFexposure level with any desired granularity.

FIG. 11 shows a table 168 illustrating one example of how the secondindicator may be a 3-bit indicator for identifying different maximumuplink duty cycles MAX_ULDC or optimal uplink duty cycles OPT_ULDC tobase station 8. As shown in FIG. 11 , the first indicator may have afirst value (e.g., “0”) when the (new/suggested/requested) uplink dutycycle (e.g., maximum uplink duty cycle MAX_ULDC or optimal uplink dutycycle OPT_ULDC) is 5%, a second value when the uplink duty cycle is 10%,a third value when the uplink duty cycle is 15%, etc.

FIG. 12 shows a table 170 illustrating one example of how the secondindicator may be a 4-bit indicator for identifying different maximumuplink duty cycles MAX_ULDC or optimal uplink duty cycles OPT_ULDC tobase station 8 (e.g., with finer granularity than the 3-bit example ofFIG. 11 ). As shown in FIG. 12 , the first indicator may have a firstvalue (e.g., “0”) when the (new/suggested/requested) uplink duty cycle(e.g., maximum uplink duty cycle MAX_ULDC or optimal uplink duty cycleOPT_ULDC) is 5%, a second value when the uplink duty cycle is 7.5%, athird value when the uplink duty cycle is 10%, etc. In tables 168 and170, a UL duty cycle of 100% corresponds to UL transmission by device 10in all UL times slots. The examples of FIGS. 11 and 12 are merelyillustrative and, in general, each value for the second indicator maycorrespond to any desired uplink duty cycles having any desired degreeof coarseness. In general, the second indicator may include any desirednumber of bits to report RF exposure level with any desired granularity.

FIG. 13 is a flow chart of illustrative operations involved in using theMAC CE to report RF exposure level RFE_LEVEL to base station 8 to allowbase station 8 to adjust the UL duty cycle of device 10 or otherwisehelp to ensure that device 10 satisfies RFE regulations. Operations172-176 of FIG. 13 may be performed by device 10. Operations 178 and 180of FIG. 13 may be performed by base station 8 and/or other portions ofnetwork 6.

At operation 172, device 10 may transmit uplink signals UL_SIG usingcurrent maximum uplink duty cycle ULDC_CURR. Device 10 may gather sensordata SENS for performing proximity detection operations. Device 10 maybegin to generate uplink reports such as uplink report UL_RPT. Uplinkreport UL_RPT may include information identifying the RF exposure levelRFE_LEVEL produced by uplink signals UL_SIG. Once device 10 has detectedan external object (e.g., user 50) at, adjacent, or proximate to thetransmit antenna(s) on device 10 (e.g., while performing proximitydetection operations), this may be indicative of a potential RFE eventand processing may proceed to operation 174. Detection of the externalobject during proximity detection operations may sometimes be referredto herein as detection of an RFE event at device 10. This example ismerely illustrative and, in general, processing may proceed to operation174 in response to any desired trigger condition. As examples,processing may proceed to operation 174 in response to a decrease in ULtransmit power (e.g., associated with device 10 being in close proximityto the base station), in response to detecting that device 10 is at apredetermined distance from base station 8 or in a predeterminedpathloss condition (e.g., based on pathloss values generated at device10, wireless performance metric data gathered at device 10, etc.), etc.In other words, detecting the proximity of external object 46 or a userneed not be the trigger condition for beginning a dynamic adjustment tothe UL duty cycle and coordination therefor with the network.

At operation 174, device 10 may transmit uplink report UL_RPT to basestation 8 over a MAC CE. The uplink report UL_RPT may, for example,include a first indicator that identifies the RF exposure levelRFE_LEVEL produced by device 10 (e.g., while processing operation 172).

At operation 178, base station 8 may receive uplink report UL_RPT fromdevice 10. UL scheduler 122 (FIG. 7 ) may generate an updated ULschedule for the specific UE device that transmitted the uplink report(device 10) based on the RF exposure level RFE_LEVEL identified by thefirst indicator in uplink report UL_RPT. The updated UL schedule mayinclude a limitation to the UL scheduling for device 10 (e.g., in thetime domain), such that the updated UL schedule identifies/implements anupdated maximum UL duty cycle for device 10 that is less than currentmaximum uplink duty cycle ULDC_CURR. If the current maximum UL dutycycle ULDC_CURR includes UL transmissions during every time slot over agiven period, the updated maximum UL duty cycle may, for example, grantdevice 10 UL transmissions during 75% of the time slots over the givenperiod, 50% of the time slots over the given period, etc.

At operation 180, base station 8 may transmit a feedback signal todevice 10 that includes an uplink grant such as uplink grant UL_GRANT ofFIG. 7 (e.g., over the PDCCH). Uplink grant UL_GRANT may instruct device10 perform subsequent communications according to its updated ULschedule (e.g., using the updated maximum UL duty cycle implemented bythe updated UL schedule).

At operation 176, device 10 may receive the feedback signal and uplinkgrant UL_GRANT from base station 8. Device 10 may then begintransmitting uplink signals UL_SIG according to uplink grant UL_GRANT(e.g., according to the updated UL schedule for device 10). Uplink grantUL_GRANT may configure device 10 to transmit uplink signals UL_SIG usingthe updated maximum UL duty cycle (e.g., by performing UL transmissionswithin time slots granted to device 10 by the updated UL schedule fordevice 10). In this way, device 10 may continue to perform ULtransmission while satisfying regulatory limits on RF energy exposureand without reducing transmit power level.

Device 10 may continue to produce RF exposure values RFE_LEVEL duringthe processing of operations 174 and 176. Device 10 may continue to usethe updated maximum UL duty cycle for uplink transmission until device10 (e.g., RFE level calculation circuitry 132) identifies that there hasbeen a change in RF exposure level RFE_LEVEL. Once there has been achange in RF exposure level RFE_LEVEL, device 10 may produce a newuplink report UL_RPT that identifies the new RF exposure level RFE_LEVELand processing may loop back to operation 174 via path 182 to report thenew RF exposure level RFE_LEVEL to base station 8 (e.g., using the newuplink report UL_RPT). Base station 8 may then accommodate the change inRF exposure level (e.g., by granting device 10 an increased maximum ULduty cycle when RF exposure level RFE_LEVEL decreases and/or a decreasedmaximum UL duty cycle when RF exposure level RFE_LEVEL increases).

The example of FIG. 13 is merely illustrative. The handshake procedureof operations 180 and 176 is not necessary and, if desired, operations180 and 176 may be omitted. In these examples, the UL scheduler maysimply begin to perform communications according to the updated ULschedule, which effectively configures device 10 to implement theupdated maximum duty cycle, without confirming the change to device 10in a separate DL transmission (feedback signal). If desired, the networkmay schedule other changes such as changes in the UL modulation schemeused by device 10 and/or an MPR for device 10 in addition to or insteadof a change in UL duty cycle in order to allow device 10 to comply withRFE regulations while performing communications with satisfactory ULthroughput given the current pathloss environment for device 10.

FIG. 14 is a flow chart of illustrative operations involved in using aMAC CE to report maximum uplink duty cycle MAX_ULDC or optimal uplinkduty cycle OPT_ULDC to base station 8 to instruct base station 8 toadjust the UL duty cycle of device 10 to maximum uplink duty cycleMAX_ULDC or optimal uplink duty cycle OPT_ULDC. Operations 172, 184, and186 of FIG. 14 may be performed by device 10. Operations 188 and 190 ofFIG. 14 may be performed by base station 8 and/or other portions ofnetwork 6.

At operation 172, device 10 may transmit uplink signals UL_SIG usingcurrent maximum uplink duty cycle ULDC_CURR. Device 10 may gather sensordata SENS for performing proximity detection operations. Device 10 maybegin to generate uplink reports such as uplink report UL_RPT. Uplinkreport UL_RPT may include information identifying maximum uplink dutycycle MAX_ULDC or optimal uplink duty cycle OPT_ULDC. Once device 10 hasdetected an external object (e.g., user 50) at, adjacent, or proximateto the transmit antenna(s) on device 10, this may be indicative of apotential RFE event and processing may proceed to operation 184. Thisexample is merely illustrative and, in general, processing may proceedto operation 184 in response to any desired trigger condition. Asexamples, processing may proceed to operation 184 in response to adecrease in UL transmit power (e.g., associated with device 10 being inclose proximity to the base station), in response to detecting thatdevice 10 is at a predetermined distance from base station 8 or in apredetermined pathloss condition (e.g., based on pathloss valuesgenerated at device 10, wireless performance metric data gathered atdevice 10, etc.), etc. In other words, detecting the proximity ofexternal object 46 or a user need not be the trigger condition forbeginning a dynamic adjustment to the UL duty cycle and coordinationtherefor with the network.

At operation 184, device 10 may transmit uplink report UL_RPT to basestation 8 over MAC CE. The uplink report UL_RPT may, for example,include a second indicator that identifies the maximum uplink duty cycleMAX_ULDC or optimal uplink duty cycle OPT_ULDC identified by device 10(e.g., as produced while processing operation 172).

At operation 188, base station 8 may receive uplink report UL_RPT fromdevice 10. UL scheduler 122 (FIG. 7 ) may generate an updated ULschedule for the specific UE device that transmitted the uplink report(device 10) based on the maximum uplink duty cycle MAX_ULDC or optimaluplink duty cycle OPT_ULDC identified by the second indicator in uplinkreport UL_RPT. The updated UL schedule may include a limitation to theUL scheduling for device 10 (e.g., in the time domain), such that theupdated UL schedule identifies/implements maximum uplink duty cycleMAX_ULDC or optimal uplink duty cycle OPT_ULDC, as identified/requestedby device 10.

If desired, base station 8 (e.g., UL scheduler 122) may determinewhether base station 8 and/or network 6 is capable of limiting the ULscheduling for device 10 to implement maximum uplink duty cycle MAX_ULDCor optimal uplink duty cycle OPT_ULDC (e.g., by determining whether thenew proposed uplink duty cycle is compatible with the capabilities ofbase station 8, whether the new proposed uplink duty cycle can be usedwithout unfairly burdening communications for other UE devices in cell40, whether load balancing within cell 40 would support the new proposeduplink duty cycle, etc.). If base station 8 or network 6 are incapableof limiting the UL scheduling for device 10 to implement maximum uplinkduty cycle MAX_ULDC or optimal uplink duty cycle OPT_ULDC, the updatedUL schedule for device 10 may call for a reduction in the maximumtransmit power level of device 10 (e.g., an MPR) without a change to theUL duty cycle of device 10.

At operation 190, base station 8 may transmit a feedback signal todevice 10 that includes an uplink grant such as uplink grant UL_GRANT ofFIG. 7 (e.g., over the PDCCH). Uplink grant UL_GRANT may instruct device10 to perform subsequent communications according to its updated ULschedule (e.g., using the maximum uplink duty cycle MAX_ULDC or optimaluplink duty cycle OPT_ULDC requested/proposed by device 10). If basestation 8 or network 6 are incapable of limiting the UL scheduling fordevice 10 to implement maximum uplink duty cycle MAX_ULDC or optimaluplink duty cycle OPT_ULDC, the uplink grant UL_GRANT may instructdevice 10 to perform subsequent communications using current maximumuplink duty cycle ULDC_CURR with an MPR.

At operation 186, device 10 may receive the feedback signal and uplinkgrant UL_GRANT from base station 8. Device 10 may then begintransmitting uplink signals UL_SIG according to uplink grant UL_GRANT(e.g., according to the updated UL schedule for device 10). Uplink grantUL_GRANT may configure device 10 to transmit uplink signals UL_SIG usingmaximum uplink duty cycle MAX_ULDC or optimal uplink duty cycleOPT_ULDC. If base station 8 or network 6 are incapable of limiting theUL scheduling for device 10 to implement maximum uplink duty cycleMAX_ULDC or optimal uplink duty cycle OPT_ULDC, the uplink grantUL_GRANT may configure device 10 to transmit the uplink signals usingcurrent uplink duty cycle ULDC_CURR with an MPR. In this way, device 10may continue to perform UL transmission while satisfying regulatorylimits on RF energy exposure. In addition, by identifying optimal uplinkduty cycle OPT_ULDC in uplink report UL_RPT when optimal uplink dutycycle OPT_ULDC is less than maximum uplink duty cycle MAX_ULDC (e.g.,while processing operation 152 of FIG. 9 ), device 10 may maximize itsUL throughput regardless of the distance between device 10 and basestation 8 within cell 40.

Device 10 may continue to produce maximum uplink duty cycles MAX_ULDC oroptimal uplink duty cycles OPT_ULDC during the processing of operations174 and 176. Device 10 may continue to use the maximum UL duty cyclegranted in uplink grant UL_GRANT until device 10 (e.g., maximum UL dutycycle calculation circuitry 136) identifies that there has been a changein maximum uplink duty cycle MAX_ULDC or optimal uplink duty cycleOPT_ULDC. Once there has been a change in maximum uplink duty cycleMAX_ULDC or optimal uplink duty cycle OPT_ULDC, device 10 may produce anew uplink report UL_RPT that identifies the new maximum uplink dutycycle MAX_ULDC or optimal uplink duty cycle OPT_ULDC and processing mayloop back to operation 184 via path 192 to report the new maximum uplinkduty cycle MAX_ULDC or optimal uplink duty cycle OPT_ULDC to basestation 8 (e.g., using the new uplink report UL_RPT). Base station 8 maythen accommodate the change in maximum uplink duty cycle MAX_ULDC oroptimal uplink duty cycle OPT_ULDC requested by device 10.

The example of FIG. 14 is merely illustrative. The handshake procedureof operations 190 and 186 is not necessary and, if desired, operations190 and 186 may be omitted. In these examples, the UL scheduler maysimply begin to perform communications according to the updated ULschedule, which effectively configures device 10 to implement MAX_ULDCor OPT_ULDC, without confirming the change to device 10 in a separate DLtransmission (feedback signal). If desired, the network may scheduleother changes such as changes in the UL modulation scheme used by device10 and/or an MPR for device 10 in addition to or instead of a change inUL duty cycle in order to allow device 10 to comply with RFE regulationswhile performing communications with satisfactory UL throughput giventhe current pathloss environment for device 10.

The examples of FIGS. 13 and 14 may be combined if desired (e.g., byincluding both the first indicator identifying RF exposure levelRFE_LEVEL and the second indicator identifying maximum uplink duty cycleMAX_ULDC or optimal uplink duty cycle OPT_ULDC in the uplink reportUL_RPT transmitted over the MAC CE). In these examples, base station 8may assign device 10 an updated maximum UL duty cycle as generated atbase station 8, or that is equal to maximum uplink duty cycle MAX_ULDCor optimal uplink duty cycle OPT_ULDC, when the network is able toaccommodate. If the network is unable to accommodate any change in themaximum UL duty cycle, base station 8 may instruct device 10 to performan MPR without adjusting duty cycle to ensure that device 10 is able tocontinue to satisfy RFE regulations.

The methods and operations described above in connection with FIGS. 1-14may be performed by the components of device 10 and/or base station 8using software, firmware, and/or hardware (e.g., dedicated circuitry orhardware). Software code for performing these operations may be storedon non-transitory computer readable storage media (e.g., tangiblecomputer readable storage media) stored on one or more of the componentsof device 10 (e.g., storage circuitry 20 of FIG. 1 ). The software codemay sometimes be referred to as software, data, instructions, programinstructions, or code. The non-transitory computer readable storagemedia may include drives, non-volatile memory such as non-volatilerandom-access memory (NVRAM), removable flash drives or other removablemedia, other types of random-access memory, etc. Software stored on thenon-transitory computer readable storage media may be executed byprocessing circuitry on one or more of the components of device 10and/or base station 8 (e.g., processing circuitry 22 of FIG. 1 , etc.).The processing circuitry may include microprocessors, central processingunits (CPUs), application-specific integrated circuits with processingcircuitry, or other processing circuitry.

Device 10 may gather and/or use personally identifiable information. Itis well understood that the use of personally identifiable informationshould follow privacy policies and practices that are generallyrecognized as meeting or exceeding industry or governmental requirementsfor maintaining the privacy of users. In particular, personallyidentifiable information data should be managed and handled so as tominimize risks of unintentional or unauthorized access or use, and thenature of authorized use should be clearly indicated to users.

For one or more aspects, at least one of the components set forth in oneor more of the preceding figures may be configured to perform one ormore operations, techniques, processes, or methods as set forth in theexample section below. For example, the baseband circuitry as describedabove in connection with one or more of the preceding figures may beconfigured to operate in accordance with one or more of the examples setforth below. For another example, circuitry associated with a UE, basestation, network element, etc. as described above in connection with oneor more of the preceding figures may be configured to operate inaccordance with one or more of the examples set forth below in theexample section.

EXAMPLES

In the following sections, further exemplary aspects are provided.

Example 1 includes a method of operating user equipment to communicatewith a wireless base station, the method comprising: determining apreferred uplink (UL) duty cycle for use by the user equipment intransmitting uplink signals to the wireless base station; generating amessage that identifies the preferred UL duty cycle; and transmittingthe message to the wireless base station.

Example 2 includes the method of example 1 or some other example orcombination of examples herein, wherein determining the preferred ULduty cycle comprises determining the preferred UL duty cycle based atleast on a pathloss between the user equipment and the wireless basestation.

Example 3 includes the method of examples 1 or 2 or some other exampleor combination of examples herein, wherein determining the preferred ULduty cycle comprises determining the preferred UL duty cycle based atleast on a transmit power level of the user equipment.

Example 4 includes the method of any one of examples 1-3 or some otherexample or combination of examples herein, wherein determining thepreferred UL duty cycle comprises determining the preferred UL dutycycle based at least on detection of a radio-frequency exposure (RFE)event at the user equipment.

Example 5 includes the method of any one of examples 1-4 or some otherexample or combination of examples herein, further comprising: detectinga radio-frequency exposure event associated with presence of an externalobject in proximity to the user equipment.

Example 6 includes the method of example 5 or some other example orcombination of examples herein, further comprising: in response todetecting the radio-frequency exposure event, determining an additionalpreferred UL duty cycle for use by the user equipment in transmittinguplink signals to the wireless base station; generating an additionalmessage that identifies the additional preferred UL duty cycle; andtransmitting the additional message to the wireless base station.

Example 7 includes the method of any one of examples 1-6 or some otherexample or combination of examples herein, wherein transmitting themessage to the wireless base station comprises transmitting the messageover a physical uplink control channel (PUCCH).

Example 8 includes the method of example 7 or some other example orcombination of examples herein, further comprising: receiving, over aphysical downlink control channel (PDCCH), a feedback signal from thewireless base station indicative of acceptance, by the wireless basestation, of the preferred UL duty cycle for the user equipment.

Example 9 includes the method of any one of examples 1-6 or some otherexample or combination of examples herein, wherein transmitting themessage to the wireless base station comprises transmitting the messageover a physical random access channel (PRACH).

Example 10 includes the method of example 9 or some other example orcombination of examples herein, further comprising: receiving a randomaccess response (RAR) from the wireless base station indicative ofacceptance, by the wireless base station, of the preferred UL duty cyclefor the user equipment.

Example 11 includes the method of any one of examples 1-6 or some otherexample or combination of examples herein, wherein transmitting themessage to the wireless base station comprises transmitting the messagein a media access control (MAC) control element (CE).

Example 12 includes the method of example 11 or some other example orcombination of examples herein, further comprising: receiving, over aphysical downlink control channel (PDCCH), a feedback signal from thewireless base station indicative of acceptance, by the wireless basestation, of the preferred UL duty cycle for the user equipment.

Example 13 includes a method of operating user equipment to communicatewith a wireless base station, the method comprising: wirelesslytransmitting an indicator to the wireless base station, the indicatorbeing indicative of the user equipment requesting an updated maximumuplink (UL) duty cycle for use by the user equipment during a subsequentUL transmission; and after transmitting the indicator to the wirelessbase station, transmitting UL signals to the wireless base station usingthe updated maximum UL duty cycle.

Example 14 includes the method of example 13 or some other example orcombination of examples herein, wherein wirelessly transmitting theindicator comprises wirelessly transmitting the indicator in response todetecting a radio-frequency exposure (RFE) event associated withpresence of an external object in proximity to the user equipment andwherein the indicator identifies that the user equipment has detectedthe RFE event.

Example 15 includes the method of example 14 or some other example orcombination of examples herein, wherein the indicator identifies an RFElevel produced by the user equipment in transmitting the first ULsignals.

Example 16 includes the method of example 15 or some other example orcombination of examples herein, wherein the indicator comprises one ormore bits in a media access control (MAC) control element (CE).

Example 17 includes the method of example 16 or some other example orcombination of examples herein, further comprising: receiving, from thewireless base station and over a physical downlink control channel(PDCCH), a feedback signal identifying the updated maximum UL dutycycle.

Example 18 includes the method of example 16 or some other example orcombination of examples herein, wherein the indicator comprises a 3-bitindicator.

Example 19 includes the method of example 14 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator over a physical uplink controlchannel (PUCCH).

Example 20 includes the method of example 19 or some other example orcombination of examples herein, wherein transmitting the indicator overthe PUCCH comprises transmitting the indicator as one or more bits inuplink control information (UCI) of the PUCCH.

Example 21 includes the method of example 19 or some other example orcombination of examples herein, further comprising: receiving, from thewireless base station and over a physical downlink control channel(PDCCH), a feedback signal identifying the updated maximum UL dutycycle.

Example 22 includes the method of claim 21 or some other example orcombination of examples herein, wherein the feedback signal comprisesone or more bits in downlink control information (DCI) of the PDCCH.

Example 23 includes the method of example 14 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator over a physical random accesschannel (PRACH).

Example 24 includes the method of example 23 or some other example orcombination of examples herein, further comprising: receiving, from thewireless base station, a random access response (RAR) identifying thesecond maximum UL duty cycle.

Example 25 includes the method of example 14 or some other example orcombination of examples herein, further comprising: in response todetecting the RFE event, identifying a suggested maximum UL duty cyclethat allows the user equipment to satisfy a predetermined limit on RFE.

Example 26 includes the method of example 13 or some other example orcombination of examples herein, wherein the indicator identifies thesuggested maximum UL duty cycle.

Example 27 includes the method of example 26 or some other example orcombination of examples herein, further comprising: receiving, from thewireless base station, a feedback signal identifying that the wirelessbase station has accepted use, by the user equipment, of the suggestedmaximum UL duty cycle as the updated maximum UL duty cycle.

Example 28 includes the method of example 27 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator over a physical uplink controlchannel (PUCCH) and wherein receiving the feedback signal comprisesreceiving the feedback signal over a physical downlink control channel(PDCCH).

Example 29 includes the method of example 27 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator over a random access channel (RACH)and wherein receiving the feedback signal comprises receiving a randomaccess response (RAR).

Example 30 includes the method of example 27 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator in a media access control (MAC)control element (CE) and wherein receiving the feedback signal comprisesreceiving the feedback signal over a physical downlink control channel(PDCCH).

Example 31 includes the method of example 26 or some other example orcombination of examples herein, further comprising: receiving, from thewireless base station, a feedback signal identifying the updated maximumUL duty cycle, wherein the suggested maximum UL duty cycle is differentfrom the updated maximum UL duty cycle.

Example 32 includes the method of example 31 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator over a physical uplink controlchannel (PUCCH) and wherein receiving the feedback signal comprisesreceiving the feedback signal over a physical downlink control channel(PDCCH).

Example 33 includes the method of example 31 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator over a random access channel (RACH)and wherein receiving the feedback signal comprises receiving a randomaccess response (RAR).

Example 34 includes the method of example 31 or some other example orcombination of examples herein, wherein transmitting the indicatorcomprises transmitting the indicator in a media access control (MAC)control element (CE) and wherein receiving the feedback signal comprisesreceiving the feedback signal over a physical downlink control channel(PDCCH).

Example 35 includes the method of example 26 or some other example orcombination of examples herein, wherein the indicator comprises aplurality of bits in a media access control (MAC) control element (CE).

Example 36 includes the method of example 35 or some other example orcombination of examples herein, further comprising: receiving, from thewireless base station and over a physical downlink control channel(PDCCH), a feedback signal identifying that the wireless base stationhas accepted use, by the user equipment, of the suggested maximum ULduty cycle as the updated maximum UL duty cycle.

Example 37 includes the method of example 35 or some other example orcombination of examples herein, further comprising: receiving, from thewireless base station and over a physical downlink control channel(PDCCH), a feedback signal identifying the updated maximum UL dutycycle, wherein the updated maximum UL duty cycle is different from thesuggested maximum UL duty cycle.

Example 38 includes the method of example 35 or some other example orcombination of examples herein, wherein the indicator comprises a 3-bitindicator.

Example 39 includes the method of example 35 or some other example orcombination of examples herein, wherein the indicator comprises a 4-bitindicator.

Example 40 includes the method of example 13 or some other example orcombination of examples herein, wherein the updated maximum UL dutycycle is less than an initial maximum UL duty cycle used by the userequipment for UL transmission prior to transmitting the indicator.

Example 41 includes a method of operating a wireless base station withina cell, the method comprising: receiving uplink (UL) signals transmittedusing a first maximum UL duty cycle by a user equipment device in thecell; wirelessly receiving an indicator transmitted by the userequipment device; and generating, based on the indicator, a UL schedulefor the user equipment device that implements a second maximum UL dutycycle that is less than the first maximum UL duty cycle.

Example 42 includes the method of example 41 or some other example orcombination of examples herein, wherein the indicator comprises one ormore bits transmitted by the user equipment device over a physicaluplink control channel (PUCCH).

Example 43 includes the method of example 42 or some other example orcombination of examples herein, further comprising: transmitting afeedback signal to the user equipment device over a physical downlinkcontrol channel (PDCCH), wherein the feedback signal instructs the userequipment device to transmit additional UL signals at the second maximumUL duty cycle.

Example 44 includes the method of example 43 or some other example orcombination of examples herein, wherein the indicator identifies thesecond maximum UL duty cycle.

Example 45 includes the method of example 43 or some other example orcombination of examples herein, wherein the indicator identifies a thirdmaximum UL duty cycle that is different than the first maximum UL dutycycle and that is different than the second maximum UL duty cycle.

Example 46 includes the method of example 41 or some other example orcombination of examples herein, wherein the indicator comprises one ormore bits transmitted by the user equipment device over a random accesschannel (RACH).

Example 47 includes the method of example 46 or some other example orcombination of examples herein, further comprising: transmitting arandom access response (RAR) to the user equipment device, wherein theRAR instructs the user equipment device to transmit additional ULsignals at the second maximum UL duty cycle.

Example 48 includes the method of example 47 or some other example orcombination of examples herein, wherein the indicator identifies thesecond maximum UL duty cycle.

Example 49 includes the method of example 47 or some other example orcombination of examples herein, wherein the indicator identifies a thirdmaximum UL duty cycle that is different than the first maximum UL dutycycle and that is different than the second maximum UL duty cycle.

Example 50 includes the method of example 41 or some other example orcombination of examples herein, wherein the indicator comprises one ormore bits transmitted by the user equipment device in a media accesscontrol (MAC) control element (CE).

Example 51 includes the method of example 50 or some other example orcombination of examples herein, further comprising: transmitting afeedback signal to the user equipment device over a physical downlinkcontrol channel (PDCCH), wherein the feedback signal instructs the userequipment device to transmit additional UL signals at the second maximumUL duty cycle.

Example 52 includes the method of example 51 or some other example orcombination of examples herein, wherein the indicator identifies thesecond maximum UL duty cycle.

Example 53 includes the method of example 52 or some other example orcombination of examples herein, further comprising: determining whetherthe wireless base station can support the second maximum UL duty cycle;generating the UL schedule when the wireless base station can supportthe second maximum UL cycle; and instructing the user equipment deviceto perform a maximum transmit power reduction when the wireless basestation cannot support the second maximum UL cycle.

Example 54 includes the method of example 51 or some other example orcombination of examples herein, wherein the indicator identifies a thirdmaximum UL duty cycle that is different than the first maximum UL dutycycle and that is different than the second maximum UL duty cycle.

Example 55 includes the method of example 41 or some other example orcombination of examples herein, wherein the indicator comprises aradio-frequency exposure (RFE) level produced by the user equipmentdevice in transmitting the UL signals using the first maximum UL dutycycle.

Example 56 includes an electronic device operable in an environment thatincludes a wireless base station, the electronic device comprising: oneor more antennas; one or more sensors configured to generate sensor dataindicative of proximity of an external object to the one or moreantennas; a transceiver configured to transmit uplink (UL) signals overthe one or more antennas using a first maximum UL duty cycle; and one ormore processors configured to generate a radio-frequency exposure (RFE)level based at least on the sensor data and the first maximum UL dutycycle, wherein the transceiver is configured to transmit informationidentifying the RFE level to the wireless base station.

Example 57 includes the electronic device of example 56 or some otherexample or combination of examples herein, wherein the one or moreprocessors is further configured to: identify a current amount of RFEbased at least on the sensor data and the first maximum UL duty cycle;and generate the RFE level based on the current amount of RFE and apredetermined RFE limit.

Example 58 includes the electronic device of example 57 or some otherexample or combination of examples herein, wherein the one or moreprocessors is further configured to: generate a second maximum UL dutycycle that is different from the first maximum UL duty cycle based atleast on the predetermined RFE limit, the current amount of RFE, and thefirst maximum UL duty cycle, wherein the transceiver is configured totransmit information identifying the second maximum UL duty cycle to thewireless base station.

Example 59 includes the electronic device of example 58 or some otherexample or combination of examples herein, wherein the one or moreprocessors is further configured to: identify a pathloss between theelectronic device and the wireless base station; and generate a thirdmaximum UL duty cycle that is different from the first maximum UL dutycycle and the second maximum UL duty cycle based at least on thepathloss between the electronic device and the wireless base station.

Example 60 includes the electronic device of example 59 or some otherexample or combination of examples herein, wherein the transceiver isconfigured to: transmit the third maximum UL duty cycle to the wirelessbase station when the third maximum UL duty cycle is lower than thesecond maximum UL duty cycle.

Example 61 includes the electronic device of example 56 or some otherexample or combination of examples herein wherein, after transmittingthe information identifying the RFE level, the transceiver is configuredto receive an uplink grant from the wireless base station that instructsthe transceiver to transmit additional UL signals over the one or moreantennas using a second maximum UL duty cycle that is less than thefirst maximum UL duty cycle.

Example 62 includes the electronic device of example 56 or some otherexample or combination of examples herein, wherein the transceiver isconfigured to transmit the information identifying the RFE level using amedia access control (MAC) control element (CE).

Example 63 may include an apparatus comprising means to perform one ormore elements of a method described in or related to any of examples1-62 or any combination thereof, or any other method or processdescribed herein.

Example 64 may include one or more non-transitory computer-readablemedia comprising instructions to cause an electronic device, uponexecution of the instructions by one or more processors of theelectronic device, to perform one or more elements of a method describedin or related to any of examples 1-62 or any combination thereof, or anyother method or process described herein.

Example 65 may include an apparatus comprising logic, modules, orcircuitry to perform one or more elements of a method described in orrelated to any of examples 1-62 or any combination thereof, or any othermethod or process described herein.

Example 66 may include a method, technique, or process as described inor related to any of examples 1-62 or any combination thereof, orportions or parts thereof.

Example 67 may include an apparatus comprising: one or more processorsand one or more non-transitory computer-readable storage mediacomprising instructions that, when executed by the one or moreprocessors, cause the one or more processors to perform the method,techniques, or process as described in or related to any of examples1-62, or any combination thereof, or portions thereof.

Example 68 may include a signal as described in or related to any ofexamples 1-62, or any combination thereof, or portions or parts thereof.

Example 69 may include a datagram, information element, packet, frame,segment, PDU, or message as described in or related to any of examples1-62, or any combination thereof, or portions or parts thereof, orotherwise described in the present disclosure.

Example 70 may include a signal encoded with data as described in orrelated to any of examples 1-62, or any combination thereof, or portionsor parts thereof, or otherwise described in the present disclosure.

Example 71 may include a signal encoded with a datagram, IE, packet,frame, segment, PDU, or message as described in or related to any ofexamples 1-62, or any combination thereof, or portions or parts thereof,or otherwise described in the present disclosure.

Example 72 may include an electromagnetic signal carryingcomputer-readable instructions, wherein execution of thecomputer-readable instructions by one or more processors is to cause theone or more processors to perform the method, techniques, or process asdescribed in or related to any of examples 1-62, or any combinationthereof, or portions thereof.

Example 73 may include a computer program comprising instructions,wherein execution of the program by a processing element is to cause theprocessing element to carry out the method, techniques, or process asdescribed in or related to any of examples 1-62, or any combinationthereof, or portions thereof.

Example 74 may include a signal in a wireless network as shown anddescribed herein.

Example 75 may include a method of communicating in a wireless networkas shown and described herein.

Example 76 may include a system for providing wireless communication asshown and described herein.

Example 77 may include a device for providing wireless communication asshown and described herein.

Any of the above-described examples may be combined with any otherexample (or combination of examples), unless explicitly statedotherwise. The foregoing description of one or more implementationsprovides illustration and description but is not intended to beexhaustive or to limit the scope of aspects to the precise formdisclosed.

The foregoing is merely illustrative and various modifications can bemade by those skilled in the art without departing from the scope andspirit of the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

1. A method of operating user equipment to communicate with a wirelessbase station, the method comprising: generating a message thatidentifies a preferred uplink (UL) duty cycle for use by the userequipment in transmitting uplink signals to the wireless base station;and transmitting the message to the wireless base station.
 2. The methodof claim 1, further comprising generating the preferred UL duty cyclebased at least on a pathloss between the user equipment and the wirelessbase station.
 3. The method of claim 1, further comprising generatingthe preferred UL duty cycle based at least on a transmit power level ofthe user equipment.
 4. The method of claim 1, further comprisinggenerating the preferred UL duty cycle based at least on detection of aradio-frequency exposure (RFE) event at the user equipment.
 5. Themethod of claim 4, further comprising: generating an additional messagethat identifies an additional preferred UL duty cycle for use by theuser equipment in transmitting uplink signals to the wireless basestation; and transmitting the additional message to the wireless basestation.
 6. (canceled)
 7. The method of claim 1, wherein transmittingthe message to the wireless base station comprises transmitting themessage over a physical uplink control channel (PUCCH), the methodfurther comprising: receiving, over a physical downlink control channel(PDCCH), a feedback signal from the wireless base station indicative ofacceptance, by the wireless base station, of the preferred UL duty cyclefor the user equipment.
 8. (canceled)
 9. The method of claim 1, whereintransmitting the message to the wireless base station comprisestransmitting the message over a physical random access channel (PRACH),the method further comprising: receiving a random access response (RAR)from the wireless base station indicative of acceptance, by the wirelessbase station, of the preferred UL duty cycle for the user equipment. 10.(canceled)
 11. The method of claim 1, wherein transmitting the messageto the wireless base station comprises transmitting the message in amedia access control (MAC) control element (CE), the method furthercomprising: receiving, over a physical downlink control channel (PDCCH),a feedback signal from the wireless base station indicative ofacceptance, by the wireless base station, of the preferred UL duty cyclefor the user equipment.
 12. (canceled)
 13. A method of operating userequipment to communicate with a wireless base station, the methodcomprising: wirelessly transmitting an indicator to the wireless basestation, the indicator being indicative of the user equipment requestingan updated maximum uplink (UL) duty cycle for use by the user equipmentduring a subsequent UL transmission; and after transmitting theindicator to the wireless base station, transmitting UL signals to thewireless base station using the updated maximum UL duty cycle.
 14. Themethod of claim 13 wherein wirelessly transmitting the indicatorcomprises wirelessly transmitting the indicator in response to detectinga radio-frequency exposure (RFE) event associated with presence of anexternal object in proximity to the user equipment and wherein theindicator identifies that the user equipment has detected the RFE event,and wherein the indicator identifies an RFE level produced by the userequipment in transmitting the first UL signals.
 15. (canceled)
 16. Themethod of claim 14, wherein the indicator comprises one or more bits ina media access control (MAC) control element (CE).
 17. The method ofclaim 14, further comprising: receiving, from the wireless base stationand over a physical downlink control channel (PDCCH), a feedback signalidentifying the updated maximum UL duty cycle.
 18. (canceled)
 19. Themethod of claim 13, wherein transmitting the indicator comprisestransmitting the indicator as one or more bits in uplink controlinformation (UCI) of a physical uplink control channel (PUCCH). 20.(canceled)
 21. The method of claim 13, further comprising: receiving,from the wireless base station and over a physical downlink controlchannel (PDCCH), a feedback signal identifying the updated maximum ULduty cycle, wherein the feedback signal comprises one or more bits indownlink control information (DCI) of the PDCCH.
 22. (canceled)
 23. Themethod of claim 13, wherein transmitting the indicator comprisestransmitting the indicator over a physical random access channel(PRACH), the method further comprising: receiving, from the wirelessbase station, a random access response (RAR) identifying the updatedmaximum UL duty cycle. 24-39. (canceled)
 40. The method of claim 13,wherein the updated maximum UL duty cycle is less than an initialmaximum UL duty cycle used by the user equipment for UL transmissionprior to transmitting the indicator.
 41. A method of operating awireless base station within a cell, the method comprising: receivinguplink (UL) signals transmitted using a first maximum UL duty cycle by auser equipment device in the cell; wirelessly receiving an indicatortransmitted by the user equipment device; and generating, based on theindicator, a UL schedule for the user equipment device that implements asecond maximum UL duty cycle that is less than the first maximum UL dutycycle.
 42. The method of claim 41, wherein the indicator comprises oneor more bits transmitted by the user equipment device over a physicaluplink control channel (PUCCH), the method further comprising:transmitting a feedback signal to the user equipment device over aphysical downlink control channel (PDCCH), wherein the feedback signalinstructs the user equipment device to transmit additional UL signals atthe second maximum UL duty cycle. 43-45. (canceled)
 46. The method ofclaim 41, wherein the indicator comprises one or more bits transmittedby the user equipment device over a random access channel (RACH), themethod further comprising: transmitting a random access response (RAR)to the user equipment device, wherein the RAR instructs the userequipment device to transmit additional UL signals at the second maximumUL duty cycle. 47-49. (canceled)
 50. The method of claim 41, wherein theindicator comprises one or more bits transmitted by the user equipmentdevice in a media access control (MAC) control element (CE), the methodfurther comprising: transmitting a feedback signal to the user equipmentdevice over a physical downlink control channel (PDCCH), wherein thefeedback signal instructs the user equipment device to transmitadditional UL signals at the second maximum UL duty cycle and whereinthe indicator identifies the second maximum UL duty cycle; determiningwhether the wireless base station can support the second maximum UL dutycycle; generating the UL schedule when the wireless base station cansupport the second maximum UL cycle; and instructing the user equipmentdevice to perform a maximum transmit power reduction when the wirelessbase station cannot support the second maximum UL cycle. 51-62.(canceled)